Murray Holland

An Atomic Clock That Stays Cool and Can Rock and Roll Without Losing Time

Steven Burrows — Thu, 09 Apr 2026 15:07:45 +0000

An Atomic Clock That Stays Cool and Can Rock and Roll Without Losing Time Steven Burrows Thu, 04/09/2026 - 09:07

Bailey Bedford / Freelance Science Communicator

A new proposal shows how guiding atoms through a controlled loop of low-energy states using an additional atomic state and a second color of light can eliminate the heating that has long hindered superradiant atomic clocks. The design also makes the laser more robust to vibrations, as coordinated interactions among atoms help keep them synchronized even when the cavity is disturbed.

In popular culture, lasers are often portrayed as portable blasters that superheat whatever they hit. Some lasers do deliver tremendous amounts of energy in reality, but for scientists and engineers, lasers often need to do more than deliver just raw power. They need to deliver a very precise frequency—color—of light.

Precise lasers open many opportunities for experiments and technologies, notably atomic clocks, which offer the most precise timekeeping in the world. Atomic clocks are used in experiments, such as searches for dark matter, and they also make possible everyday technologies, like GPS. Currently, the most precise lasers, and therefore the most precise atomic clocks, are bulky and can be disrupted by small vibrations or changes in temperature, which limits their applications.

In an article published April 9, 2026, in the journal Physical Review Letters, JILA graduate student Jarrod Reilly proposed a new laser design that may allow for greater precision while making lasers more compact and robust. The design was developed along with JILA Fellows Murray Holland and John Cooper, as well as Simon Jäger—who was formerly a JILA postdoctoral researcher and is now an international collaborator at the University of Bonn in Germany. It builds on prior research they and their colleagues at JILA have performed, and their analysis indicated that it solves multiple problems that have limited past experiments. The improvements suggest a way that future atomic clocks can be both more precise and more convenient.

“Time and frequency are the two physical quantities that humans can measure the best,” Holland says. “This high sensitivity allows us to make measurements that are incredibly precise. Pushing it further opens up new domains where we could look farther than we've ever been able to look before.”

The new design is for a type of laser called a superradiant laser, and having a reliable superradiant laser is necessary to create a new type of compact atomic clock called an active atomic clock. Superradiant lasers that could enable active atomic clocks were first proposed by JILA researchers in 2009, and JILA researchers continue to refine the technology. Active atomic clocks use similar principles to standard atomic clocks but include some important tweaks.

Both traditional and active atomic clocks take advantage of the fact that atoms have quantum states which researchers can link together using light. Light comes in quantum packets that each carry a certain amount of energy that corresponds to its frequency—how quickly the light waves oscillate. An atom can be pushed from its initial state into a higher-energy state by hitting it with light of the right frequency. An atom with extra energy will sometimes release light to return to a lower-energy state. The consistent waves of light associated with a particular transition between chosen high- and low-energy atomic states can play a role similar to the steady swinging of a pendulum in a grandfather clock.

Traditional atomic clocks shine a laser on atoms and monitor when the atoms interact with the light at the correct frequency. An active atomic clock, instead, uses many atoms releasing light to create a laser with the desired frequency.

Making an active atomic clock requires getting all the atoms to work together to produce the superradiant laser. If too few atoms emit light at a time, nothing will be observed, and if different atoms simultaneously emit light in the wrong way, the resulting wave that is generated may lose coherence and become unusable.

To coordinate atoms, researchers put them in a special cavity where light bounces between two mirrors. The cavity maintains the frequency of light needed to interact with the atoms and encourages them to synchronize. The process resembles performers coordinating their dance steps by all listening to the same music.

In 2012, Holland collaborated with JILA Fellow James Thompson and demonstrated in experiments that superradiant lasers worked. But there was a hiccup: The process only worked for short periods at a time, and the laser ended up as a series of pulses, which couldn’t be used directly as an active atomic clock. The chamber coordinated the atoms releasing the desired frequency of light. However, when the atoms were put into the chosen energetic state, each atom emitted a small amount of extra light without any coordination. This unpredictable emission resulted in random motion that heated the atoms and eventually disrupted the synchronization needed for superradiance.

The new proposal suggests a method to eliminate the heating. Reilly, who is the first author of the paper, realized the atoms could be guided throughout the entire process and avoid the heating. Reilly observed that utilizing an additional state in the atom allows an experiment to use a different color of light to direct atoms through the troublesome step.

To make it work, he had to select an atom with two very similar states when the atom has as little energy as possible. Researchers can supply light to move the atoms between the two low-energy states. Then, placing the atoms in that additional low-energy state allows a second color of light to be introduced into a cavity that coordinates how the atoms move to the selected energetic state.

Now, the atoms are guided through more than the single dance step of producing the desired frequency. The experiment directs the atoms through a full loop of states, with a scientist controlling where all the energy goes. Each step is carefully managed, and the extra energy is predictably directed away from the atoms, where it can be easily handled.

The group used ideas from particle physics to develop a simulation of the quantum process that Reilly had identified. The simulation showed that the process should eliminate the heating that had previously prevented the creation of active atomic clocks using superradiant lasers.

“This heating rate should be so low that it would be easily manageable in a real apparatus,” Holland says.

But they went beyond eliminating the heating problem. They also discovered that the new design made the laser less sensitive to the shaking of the chamber than prior methods. The atoms didn’t just interact with the light in the cavity but with each other, like performers who can hear each other singing to the music. The new controlled transitions and extra light bouncing back and forth in the cavity should help the atoms interact and remain coordinated. If the cavity is slightly disrupted, it is like the music temporarily cutting out or being distorted, but the singing helps keep the performers coordinated nonetheless.

With increased coordination, the atoms should depend largely on synchronization with each other and less on the cavity, so shaking the cavity shouldn’t have much effect. The researchers used the simulation to show that there are certain ways to set up the experiment in which the frequency of the laser is not sensitive to vibrations of the cavity’s mirrors at all.

“What they're measuring in a clock is that frequency,” Reilly says. “The big-game-changer is that it becomes completely insensitive to vibrations, which people have spent 20 years trying to overcome. You could jump up and down next to the experiment, and in a regular clock, you'd see the color change, but you can jump up and down next to our clock and not see the color change. It should stay stable.”

The researchers also used their simulations to show that even when individual atoms fall out of sync with the others, it shouldn’t disrupt the superradiance—a known problem with some previous methods.

The team says they hope to see the proposal realized in an experiment, and they also want to combine their idea with another concept for the next generation of clocks: nuclear clocks. Nuclear clocks are similar to atomic clocks but use the quantum states of nuclei. The researchers believe their new superradiance technique could solve a lingering issue with nuclear clocks and provide a path to a new generation of unprecedentedly accurate timepieces.

Researchers at JILA propose a new superradiant laser design for next-generation “active” atomic clocks that eliminates atom-heating and vibration sensitivity, two major obstacles that have limited precision and practicality. By carefully guiding atoms through a controlled loop of quantum states, the approach could enable compact, robust atomic—and potentially nuclear—clocks that maintain extreme accuracy even under physical disturbances.

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JILA Joins DOE’s Quantum Systems Accelerator for Next Phase of Quantum Innovation

Steven Burrows — Tue, 04 Nov 2025 19:18:36 +0000

JILA Joins DOE’s Quantum Systems Accelerator for Next Phase of Quantum Innovation Steven Burrows Tue, 11/04/2025 - 12:18

Steven Burrows / JILA Science Communications Manager

A round glass cell (centre, in black frame) is designed to hold a gas of molecules cooled to 50 billionths of a Kelvin. Credit: Ye Group/Steven Burrows/JILA

The U.S. Department of Energy (DOE) has announced a $625 million investment to advance the next phase of the National Quantum Information Science Research Centers, a cornerstone of the National Quantum Initiative. This funding will support five centers dedicated to accelerating quantum technologies that promise transformative impacts on science, industry, and national security.

Among these centers, the Quantum Systems Accelerator (QSA)—led by Lawrence Berkeley National Laboratory—will continue its mission to develop practical quantum systems that can solve real-world problems. QSA brings together leading institutions to tackle challenges in quantum computing, sensing, and networking, aiming to bridge the gap between theoretical advances and deployable technologies.

JILA is proud to remain a key partner in QSA through the Q-SEnSE Institute, which focuses on quantum sensing and precision measurement. These capabilities are essential for applications ranging from navigation and timing to probing fundamental physics. JILA Fellow Jun Ye will lead the JILA effort, supported by senior investigators and JILA Fellows Cindy Regal, Adam Kaufman, Ana Maria Rey, James Thompson, Murray Holland, and Xun Gao—a team internationally recognized for pioneering work in quantum optics, atomic physics, and many-body systems.

“JILA is proud to remain a key partner in QSA. Through our work in both QSA and Q-SEnSE, JILA plays a leading role in advancing quantum innovations at the national and international levels,” remarked Inese Berzina-Pitcher, Executive Director for Q-SEnSE.

The next five years of QSA will focus on building scalable quantum platforms, advancing error correction, and integrating quantum devices into scientific workflows. JILA’s expertise in ultracold atoms, optical lattices, and quantum simulation will play a critical role in these goals.

For more details, read the official announcements:

Energy Department Announces $625 Million to Advance the Next Phase of National Quantum Information Science Research Centers

The Quantum Systems Accelerator Embarks on Next Five Years of Pioneering Quantum Technologies for Science

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New quantum navigation device uses atoms to measure acceleration in 3D

Steven Burrows — Wed, 11 Jun 2025 17:15:39 +0000

New quantum navigation device uses atoms to measure acceleration in 3D Steven Burrows Wed, 06/11/2025 - 11:15

Daniel Strain / ��Ҵ�ý�ƽ�� Strategic Communications

In a new study, physicists at JILA and the University of Colorado Boulder have used a cloud of atoms chilled down to incredibly cold temperatures to simultaneously measure acceleration in three dimensions—a feat that many scientists didn’t think was possible.

The device, a new type of atom “interferometer,” could one day help people navigate submarines, spacecraft, cars and other vehicles more precisely.

“Traditional atom interferometers can only measure acceleration in a single dimension, but we live within a three-dimensional world,” said Kendall Mehling, a co-author of the new study and a graduate student in the Department of Physics at ��Ҵ�ý�ƽ��. “To know where I'm going, and to know where I’ve been, I need to track my acceleration in all three dimensions.”

The researchers published their paper, titled “Vector atom accelerometry in an optical lattice,” this month in the journal Science Advances. The team included Mehling; Catie LeDesma, a postdoctoral researcher in physics; and Murray Holland, professor of physics and fellow of JILA, a joint research institute between ��Ҵ�ý�ƽ�� and the National Institute of Standards and Technology (NIST).

In 2023, NASA awarded the ��Ҵ�ý�ƽ�� researchers a $5.5 million grant through the agency’s Quantum Pathways Institute to continue developing the sensor technology.

The new device is a marvel of engineering: Holland and his colleagues employ six lasers as thin as a human hair to pin a cloud of tens of thousands of rubidium atoms in place. Then, with help from artificial intelligence, they manipulate those lasers in complex patterns—allowing the team to measure the behavior of the atoms as they react to small accelerations, like pressing the gas pedal down in your car.

Today, most vehicles track acceleration using GPS and traditional, or “classical,” electronic devices known as accelerometers. The team’s quantum device has a long way to go before it can compete with these tools. But the researchers see a lot of promise for navigation technology based on atoms.

“If you leave a classical sensor out in different environments for years, it will age and decay,” Mehling said. “The springs in your clock will change and warp. Atoms don’t age.”

Fingerprints of motion

Interferometers, in some form or another, have been around for centuries—and they’ve been used to do everything from transporting information over optical fibers to searching for gravitational waves, or ripples in the fabric of the universe.

From left to right, Kendall Mehling, Murray Holland and Catie LeDesma in their lab at ��Ҵ�ý�ƽ��. Image credit: Glenn Asakawa / ��Ҵ�ý�ƽ��

The general idea involves splitting things apart and bringing them back together, not unlike unzipping, then zipping back up a jacket.

In laser interferometry, for example, scientists first shine a laser light, then split it into two, identical beams that travel over two separate paths. Eventually, they bring the beams back together. If the lasers have experienced diverging effects along their journeys, such as gravity acting in different ways, they may not mesh perfectly when they recombine. Put differently, the zipper might get stuck. Researchers can make measurements based on how the two beams, once identical, now interfere with each other—hence the name.

In the current study, the team achieved the same feat, but with atoms instead of light.

Here’s how it works: The device currently fits on a bench about the size of an air hockey table. First, the researchers cool a collection of rubidium atoms down to temperatures just a few billionths of a degree above absolute zero.

In that frigid realm, the atoms form a mysterious quantum state of matter known as a Bose-Einstein Condensate (BEC). Carl Wieman, then a physicist at ��Ҵ�ý�ƽ��, and Eric Cornell of JILA won a Nobel Prize in 2001 for creating the first BEC.

Next, the team uses laser light to jiggle the atoms, splitting them apart. In this case, that doesn’t mean that groups of atoms are separating. Instead, each individual atom exists in a ghostly quantum state called a superposition, in which it can be simultaneously in two places at the same time.

When the atoms split and separate, those ghosts travel away from each other following two different paths. (In the current experiment, the researchers didn’t actually move the device itself but used lasers to push on the atoms, causing acceleration).

“Our Bose-Einstein Condensate is a matter-wave pond made of atoms, and we throw stones made of little packets of light into the pond, sending ripples both left and right,” Holland said. “Once the ripples have spread out, we reflect them and bring them back together where they interfere.”

When the atoms snap back together, they form a unique pattern, just like the two beams of laser light zipping together but more complex. The result resembles a thumb print on a glass.

“We can decode that fingerprint and extract the acceleration that the atoms experienced,” Holland said.

Planning with computers

The group spent almost three years building the device to achieve this feat.

“For what it is, the current experimental device is incredibly compact. Even though we have 18 laser beams passing through the vacuum system that contains our atom cloud, the entire experiment is small enough that we could deploy in the field one day,” LeDesma said.

One of the secrets to that success comes down to an artificial intelligence technique called machine learning. Holland explained that splitting and recombining the rubidium atoms requires adjusting the lasers through a complex, multi-step process. To streamline the process, the group trained a computer program that can plan out those moves in advance.

So far, the device can only measure accelerations several thousand times smaller than the force of Earth’s gravity. Currently available technologies can do a lot better.

But the group is continuing to improve its engineering and hopes to increase the performance of its quantum device many times over in the coming years. Still, the technology is a testament to just how useful atoms can be.

“We’re not exactly sure of all the possible ramifications of this research, because it opens up a door,” Holland said.

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Combining Machine Learning with Quantum Metrology: Making a Universal Quantum Sensor

Steven Burrows — Mon, 14 Apr 2025 18:18:47 +0000

Combining Machine Learning with Quantum Metrology: Making a Universal Quantum Sensor Steven Burrows Mon, 04/14/2025 - 12:18

Kenna Hughes-Castleberry / JILA Science Communicator

Simulation using the gradiometer protocol. Image credit: Steven Burrows / JILA

Atom interferometry, a technique that leverages the wavelike nature of atoms, has been pivotal in precision measurements, including satellite navigation and measuring the Earth's roundness. Traditional atom interferometry setups, however, often lack flexibility, requiring hardware modifications for performing different measurement tasks.

Addressing this limitation, JILA Fellow and University of Colorado Boulder physics professor Murray Holland and his team, along with ��Ҵ�ý�ƽ�� Engineering Professor Marco Nicotra, developed a platform that combines machine learning with atom interferometry. Recently published in Physical Review Research, their work establishes a programmable framework for quantum sensing, where, using universal programmable atom-optic “gates,” a single device can be reconfigured via software to perform a wide range of precision measurements—such as acceleration, rotation, and gravity gradients—without hardware changes.

This innovation not only advances the flexibility and efficiency of quantum sensors but also lays the groundwork for a new wave of quantum engineering in which future quantum technologies integrate AI-driven control to provide extra precision and functionality.

“Understanding the superposition and interference of particles has been at the heart of quantum for more than a century, but just now we are just beginning to develop the experimental tools to really exploit the ideas and build new future technologies,” Holland says.

Following JILA’s Legacy of Laser Stability

JILA has long been recognized as a global leader in precision measurement, particularly in laser stability and atomic control. Much of this legacy stems from the groundbreaking work of JILA and NIST Fellow Jun Ye, whose pioneering research has redefined the frontiers of ultra-stable lasers and optical atomic clocks.

Building on this tradition, Holland, along with JILA postdoctoral researcher Catie LeDesma and graduate student Kendall Mehling, used ultra-stable lasers as the foundation for their system. These lasers create the optical lattice that traps and manipulates a Bose-Einstein condensate—an ultracold cloud of atoms behaving as a single quantum wave.

To bring the system to life, the team collaborated closely with JILA electronics shop member Terry Brown, who played a critical role in designing and fine-tuning the custom circuitry required to control the lattice’s motion precisely.

“Terry Brown has been a pivotal contributor to our experiment, helping us to understand and build the ultra-low-noise radio-frequency electronics that are core components of our experimental design,” Mehling notes.

Each gate operation—such as splitting, reflecting, or stopping the atom wave-packets—was executed through carefully choreographed shifts in the lattice position. These gates acted like programmable “tiles” that could be arranged sequentially, like LEGO bricks, to build complex atom interferometer circuits. By snapping these elements together in different combinations, the team could effectively program the quantum sensor to perform various measurement tasks—all within the same physical setup.

Adding Machine Learning

What sets this project apart is how the team used machine learning to design the gates or “tiles” in their system. Instead of relying on manually tuned parameters or hard-to-find solutions of mathematical equations, the researchers turned to artificial intelligence to solve the complex problem of finding the precise lattice modulations needed to implement each gate. They used optimization algorithms to train a computer to discover how to dynamically position the optical lattice in just the right way to achieve high-fidelity quantum state transformations. This approach not only streamlined the design process but also uncovered solutions that might be non-intuitive to human inventors.

“Artificial intelligence is a trending theme in the science of today, and our experiment is no exception, where the computers find solutions to our design tasks that would be impossible to envisage without their help,” says LeDesma.

Validating Their Setup

To prove their system worked, the team ran a series of experiments with a Bose-Einstein condensate (BEC) of rubidium atoms trapped in the optical lattice. Using precision imaging, they captured the motion of the atoms in real time as each gate was applied, watching as the atom cloud split, reflected, or froze in place according to the programmed instructions. These visual results were then matched with time-of-flight measurements, where the atoms are released and their wavefunctions allowed to expand, revealing their momentum distribution—an essential tool for verifying the implementation of the state transformations.

The comparison between experimental data and the machine learning simulations showed remarkable agreement. Gates designed purely through computational optimization were realized in the lab with high fidelity, often exceeding 90% accuracy. This confirmed that the AI-designed protocols were viable and could be executed with precision in a real-world quantum system—a significant achievement in quantum control engineering.

Creating Versatile Quantum Sensors

By creating a universal gate platform for atom interferometry, Holland’s team has laid the groundwork for software-defined quantum sensors—devices that can switch functions with a new program rather than a new piece of hardware. What’s more, the fusion of AI and quantum hardware offers a pathway to optimizing these sensors for changing environments. In principle, a future sensor could learn in real time, adjusting its gate sequences on the fly to compensate for noise or to prioritize different measurement axes—opening the door to adaptive, intelligent quantum metrology.

This work is also part of NASA’s Quantum Pathways Institute (QPI), a multi-institutional effort to develop deployable quantum technologies. NASA’s vision includes mobilizing quantum sensors for use in space, where traditional systems may be too rigid or sensitive to operate effectively. The universal gate framework aligns perfectly with this goal—enabling sensors that can be reprogrammed mid-mission to adapt to new objectives or conditions in orbit, on planetary surfaces, or even deep-space missions.

“We think this technology solution that bridges quantum physics and AI will allow us to build new kinds of applications that will bring the fuzzy quantum world out of the lab and into everyday life,” Holland says.

This research was supported by NASA and the National Science Foundation.

Researchers at JILA and the University of Colorado Boulder have developed an innovative platform that combines machine learning with atom interferometry to create a universal quantum sensor. This system uses programmable atom-optic "gates" to reconfigure a single device via software for various precision measurements, such as acceleration, rotation, and gravity gradients, without the need for hardware changes.

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Meet the JILA Postdoc and Graduate Student Leading the Charge in a Multi-Million-Dollar NASA-Funded Quantum Sensing Project

Steven Burrows — Tue, 06 Aug 2024 16:27:35 +0000

Meet the JILA Postdoc and Graduate Student Leading the Charge in a Multi-Million-Dollar NASA-Funded Quantum Sensing Project Steven Burrows Tue, 08/06/2024 - 10:27

Kenna Hughes-Castleberry / JILA Science Communicator

Vacuum cell (left) showing the geometry of lattice beams (green) oriented along three orthogonal axes. The lattice beams intersect Bose-Einstein condensed atoms (red) over the angled internal optic. Although only a single probe beam (blue) is shown, probe beams are aligned to each axis of the lattice to enable imaging from any direction.

Illustration of the Blochband interferometry (BBI) system (right), using an optical lattice. The sequence shows the BEC splitting into four 2D momenta (green arrows), reflection after propagation (blue arrows), and the reverse beam splitter providing recombination (orange arrows) to form a 2D interference pattern.

Image Credit: Steven Burrows / JILA

In the quiet halls of the Duane Physics building at the University of Colorado Boulder, two JILA researchers, postdoctoral research associate Catie LeDesma and graduate student Kendall Mehling, combine machine learning with atom interferometry to create the next generation of quantum sensors. Because these quantum sensors can be applied to various fields, from satellite navigation to measuring Earth’s composition, any advancement has major implications for numerous industries.

As reported in a recent article preprint, the researchers successfully demonstrated how to build a quantum sensor using atoms moving through crystals made entirely of laser light. They applied accelerated forces to atoms along multiple directions and, using this sensor, measured the results, which closely matched values predicted by quantum theory. LeDesma and Mehling also showed that their device could accurately detect accelerations from just one run of their experiment, a feat that is very difficult to accomplish with traditional cold-atom interferometry.

The experimental setup involved a sophisticated arrangement of lasers and other optical devices to manipulate and measure atoms at ultracold temperatures. Their approach was initially met with skepticism by many in the scientific community due to the novelty of the design and absolute reliance upon nonintuitive machine learning algorithms.

“Many thought that this type of measurement wouldn’t work,” explains JILA Fellow and University of Colorado Boulder Physics professor Murray Holland, the project’s principal investigator at ��Ҵ�ý�ƽ��. “But the data is convincing.”

While the scientific community may still be coming to terms with the potential of LeDesma’s, Mehling’s, and Holland’s project to merge AMO (atomic, molecular, and optical) physics with machine learning, the unique approach has already secured a $15 million grant from NASA as part of the Quantum Pathways Institute (QPI). The Quantum Pathways Institute is centered at the Center for Space Research (CSR) in Austin, Texas, and is led by Srinivas Bettadpur and colleagues.

Other collaborators in the Quantum Pathways Institute in Boulder include JILA Fellow and ��Ҵ�ý�ƽ�� professor of physics Dana Anderson, professor of aerospace engineering Penina Axelrad, associate professor of electrical engineering Marco Nicotra, and group lead for the Sources and Detectors Group at NIST (National Institute of Standards and Technology) Michelle Stephens.

This institute is NASA’s first step in exploring the potential advantages of quantum metrology over classical sensors deployed in space. As stated on the QPI website, the quantum sensors will be placed “aboard satellites in orbit around Earth to collect mass change data—a type of measurement that can tell scientists about how ice, oceans, and bodies of water are moving and changing.” Such technology would lead to more accurate pictures of the effects of climate change and global warming on Earth.

JILA postdoctoral researcher Catie LeDesma (left) discusses the new quantum metrology set up with JILA graduate student Kendall Mehling (right)

Taking the Quantum Reins

Because their complicated nature can often span longer than the time to obtain a PhD, many research projects within the physics community are inherited by a graduate student from a graduating doctoral student. In LeDesma’s case, there was no prior graduate student to hand over a working experiment to her when she started on the project as a new graduate student in the fall of 2019.

“My introduction to the world of quantum gases was with a magneto-optical trap, or MOT,” she says. “However, to do any of the precision metrology we wanted, I needed to learn how to make a Bose-Einstein-Condensate, and there were no students in the lab who could pass on that prior knowledge.”

Considered the fifth state of matter, Bose-Einstein-Condensates (BECs) are composed of dense, ultracold clouds of gaseous atoms in the quantum regime. They have a long history at JILA, as JILA and NIST Fellow Eric Cornell and former JILA Fellow Carl Wieman were awarded the 2001 Nobel Prize in Physics for experimentally creating the first BEC.

When LeDesma arrived at JILA, just before the COVID-19 pandemic, she began to work on the BEC quantum metrology project that had formed the core doctoral work of a former graduate student Carrie Weidner, under the supervision of Professor Dana Anderson. Both Anderson and Weidner had spent years previously developing a special type of quantum metrology known as shaken-lattice interferometry, which uses controlled vibrations of a grid-like structure to measure and study the behavior of particles precisely.

The BEC quantum metrology experiment was (and still is) housed in the Duane Physics building C-wing, an area susceptible to vibration, noise, and temperature variation, all unfavorable conditions for a sensitive precision experiment.

“For about a year and a half, I had to teach myself a lot of basic experimental skills. In that time, I completely rebuilt the 780-nm laser system necessary for cooling and trapping rubidium atoms and making BEC on an atom chip using RF evaporation. This experience proved instrumental for our future work which involved moving to a newer method of achieving BEC,” LeDesma explains.

In 2021, Mehling arrived as a new graduate student in the laboratory. Together, LeDesma and Mehling made great strides in their BEC quantum sensor apparatus, including significant changes from the 2017 project. This included completely rethinking both how the experiment creates BECs and the method of performing interferometry itself, which involved a full experimental redesign and construction.

Together, they applied a contemporary method to evaporatively cool atoms with an all-optical sequence, successfully observing their first BEC with this method in the fall of 2022.

All-optical evaporation is performed within tightly focused, high-intensity laser beams. When two of these laser beams intersect, their crossing forms an optical trap where large numbers of hot atoms can be stored and collide with each other. Forced evaporative cooling is then performed by reducing the power of the laser beams. This process boils off the hot atoms similarly to the release of steam from a hot cup of coffee as it cools.

Using an all-optical method, the researchers do not need to use any magnetic fields during the cooling process, enhancing the BEC’s potential size and stability. Additionally, this design allows the BEC to be more easily transferred into an optical lattice—a structure formed by interfering laser beams that create a standing potential of light. This lattice acts like a “light crystal” that can hold and manipulate atoms in a very controlled manner, enabling their use in interferometry experiments.

Engineering Your Own Quantum Sensor

Interferometers have a long, rich history as precision metrology instruments. Optical interferometers operate by splitting, mirroring, and recombining coherent light beams, resulting in discernable phase shifts in the light’s interference pattern because of minute differences along the two paths. Measurement of these phase shifts can reveal information about the environment and enable the sensing of inertial signals such as accelerations, rotations, and gravity gradients. These measurements form the basis of commercial gyroscopes such as ring laser gyroscopes and fiber optic gyroscopes.

More recently, AMO physicists have invested considerable research into atom interferometry, where the role of light and matter are effectively switched—that is, light pulses are used to split, mirror, and recombine the matter waves of neutral atoms to measure slight changes in their environment.

LeDesma, Mehling, and Holland further modified this approach, performing interferometry while the atoms interact with an optical lattice during the entirety of their sensing sequence. Dynamic control of the lattice phase (i.e., the location of light and dark regions) according to machine-learned protocols allowed the researchers to realize the necessary interferometry components.

At the sensor's core is a custom double-MOT system built by Infleqtion, a quantum technology company. Within this ultrahigh-vacuum chamber, a combination of magnetic fields and precisely tuned laser light damp the motion of rubidium atoms with decelerations of up to 1000 m/s2, or 100 times the force of Earth’s gravity.

This cooling is achieved through Doppler cooling, a process in which lasers tuned to a color that is a slightly lower frequency than the color that the atoms typically absorb. This causes atoms to slow down when they move against the direction of the laser light. This laser force is strong as it reduces the temperature of the atoms by a factor of 10,000 in a few milliseconds.

In addition to the cooling effect of the laser light, magnetic field gradients are applied to exert a position-dependent force on the atoms. Combined, this process, known as a magneto-optical trap, or MOT, is a critical first step in many AMO experiments for quantum science.

In this common setup, the apparatus produces ultracold atoms in two distinct regions. In a lower glass chamber, dispensed atoms are initially cooled along two dimensions, and a laser push beam is used to propel the atoms vertically up through a tiny tube. They then appear and are recaptured in an upper chamber which has the pristine vacuum quality necessary to perform experiments where confining atoms for seconds is desirable.

“We produce a MOT in the bottom cell, and then we push atoms up to the 3D science chamber, where we load a three-dimensional MOT that would look maybe the size of a thumbnail,” Mehling elaborates.

The 3D MOT typically accumulates one billion cold rubidium atoms over a five-to-ten-second load time. Additional cooling is achieved by changing the chamber's magnetic field strength and further detuning the laser light from atomic resonance.

The cold and dense atoms that result are then captured by intense 15-watt laser beams to perform all-optical evaporation to degeneracy. The brightness of the beams, and therefore the trap depth, is slowly lowered to cool the atoms below the critical temperature necessary to form a BEC. For a typical experimental run, LeDesma and Mehling produce 100,000 BEC atoms at an effective temperature of below 10 nK, 300,000 times colder than the initial MOT atoms.

Following these numerous cooling steps, the BEC is then loaded into their multidimensional optical lattice. While many experiments use retroreflecting mirrors to create their optical lattices because it is easier, LeDesma and Mehling instead use counterpropagating laser beams. This design offers greater versatility and flexibility in controlling the location of the lattice nodes and antinodes but is harder and requires meticulous alignment.

“It's like taking two strands of hair and overlapping them, and they have to align perfectly to create your lattice,” Mehling adds. “It becomes more complicated because our lasers aren’t visible light; they’re in the IR (infrared) spectrum, so we can’t see them with the naked eye and have to use IR cards to detect where they are and then align them manually.”

Catie LeDesma crawls on top of the table-top apparatus as part of the laboratory rebuild

Adding AI to Quantum

The complexity of controlling pure quantum states like a BEC in an optical lattice involves numerous variables, each of which can drastically affect the outcome. The researchers employ sophisticated machine design techniques such as reinforcement learning (RL) and quantum optimal control (QOC) to develop and optimize the control sequences that manipulate the atomic wave functions within the lattice to perform interferometry.

Holland and his former graduate student Liang-Ying Chih developed much of the initial theory that the current experimental procedures for interferometry rely on. They applied reinforcement learning, a form of machine learning and artificial intelligence, to the quantum design problem and showed that atom interferometry could be done in this manner.

Additionally, LeDesma and Mehling worked alongside associate professor of electrical engineering Marco Nicotra and his former graduate student Jieqiu Shao to implement quantum optimal control algorithms to generate an alternative class of interferometry solutions. High-fidelity solutions obtained through both approaches demonstrated a successful interface between atom interferometry and computer programming.

The researchers experimentally apply these machine-generated solutions by changing the relative phase of individual lattice beams as needed.

The lattices’ counterpropagating design enables the relative phase to be adjusted by inputs from a control computer. This means that controls can be changed on the fly, and the sensor’s behavior can be changed at will by software programming rather than by modifying the experimental hardware. This programmability of their sensor allows the device to operate as either an accelerometer in one dimension or a multi-dimensional gyroscope via the flick of a virtual switch. However, initial experiments wielding this additional flexibility proved nontrivial.

“There was quite a learning curve to go through to understand how to apply the machine-learned protocols and to get the BEC atoms to do precisely what we wanted” explains Holland. “But we are now so good at it that if we find a great solution on the computer, we know with high confidence that we will be able to apply it to the experiment.”

The final component of their sensing sequence involves the detection and imaging of the atoms. A resonant probe aligned with each lattice axis enables absorption imaging of the atoms following lattice phase modulation. Absorption images of the atoms provide detailed information about the momentum and position of the atoms, allowing the researchers to reconstruct the atomic wavefunctions and measure the atoms’ response to inertial signals.

In practice, the matter-wave interference pattern from which a signal is extracted is seen by allowing atoms to fall under gravity and separate into discrete momentum components. The relative occupation of atoms in these multi-order momentum states changes with an applied inertial signal. Imaging the atoms after they have undergone interferometry and time of flight enables the researchers to reconstruct the applied signals.

In their most recent experiments, the sequencing of the machine-learned protocols allowed the experimental team to perform a special type of measurement known as two-dimensional Michelson interferometry, which is used in other apparatuses that do not involve machine learning.

LeDesma and Mehling revealed the resulting 49 momentum diffraction peaks in the atoms’ 2D interference pattern, which had not previously been seen by other experiments. Measurements of the many-order diffraction pattern provided the critical information needed to determine the magnitude and direction of external accelerations. This information was crucial for calibrating the sensor’s sensitivity, optimizing performance, and calculating the application's experimental stability.

To better understand the systems dynamics and predict their sensor’s response and performance, LeDesma and Mehling worked closely with JILA Fellow Murray Holland.

“This project works because we've been working heavily with the theorists, who can help translate all the protocols,” Mehling adds. “Murray was here sitting in the lab with us, trying to get the control protocols to work from the beginning of the project. He comes down to the lab and gets his hands dirty, and I don’t think we could oversell Murray's importance and how good of an advisor he is.”

While Holland’s research has been in quantum theory, his 30-year history of studying BEC dynamics allowed him to help guide the implementation of these novel interferometry sequences and realize the importance of their research.

“It’s impressive what Catie and Kendall have been able to achieve in such a short time,” Holland comments. “They quickly recognized what problems had to be solved and found solutions. The result is work that is opening a whole new avenue of research which will develop into a substantial field, with JILA at the forefront.”

NASA Buys In

In March 2023, the BEC quantum metrology experiment got a significant boost in funding with the help of the NASA Quantum Pathways Institute grant, a $15 million grant over five years to several universities working on applying remote quantum sensing to study the Earth’s climate.

As ��Ҵ�ý�ƽ�� has been designated as the testbed site for this grant, LeDesma and Mehling are leading the charge, along with Holland, the lead PI for the Colorado portion of the grant, and with the other ��Ҵ�ý�ƽ�� research collaborators.

Rebuilding a Laboratory in Seven Days

Away from JILA’s dampening floors and piped-in purified water and air, the C-wing of the Duane Physics Building suffers from vibrations and thermal fluctuations from the glass windows and countless students walking, biking, and skateboarding past the lab on the concrete sidewalks and paths outside.

In the fall of 2023, LeDesma and Mehling, fed up with the older building’s issues, decided to remodel the experiment, taking apart the entire apparatus and rebuilding it from the ground up.

“The temperature stability in this lab is horrendous,” LeDesma elaborates, “The temperature swings up to five degrees daily, which can greatly affect laser beam pointing stability. In our original system, this caused drifts in the alignment of the light used for all-optical evaporation as well as our lattice beams used for interferometry. We were having to realign beams at least four to five times daily to combat this.”

To compensate for these issues, LeDesma and Mehling worked with JILA’s instrument shop to create a custom climate-controlled enclosure to supply cooled, filtered air to their experimental system. However, to install this new enclosure, the experiment had to be deconstructed. The full demolition day was August 15, 2023.

“Installation of the new enclosure required us to not only remove a majority of the optics off the table but also included removing all the electronics and other elements used to control the experiment. We had to uninstall all the rack units that originally held all of these components above the optics table.” LeDesma says. “After we installed the new enclosure, we started putting optics back on the table. It took us six days to obtain our first BEC following the rebuild.”

The rebuild took seven days, not because of external pressure but because of LeDesma and Mehling's efficiency in working with their system, which they had reconfigured dozens of times.

Their experimental rebuild has proven instrumental in the researchers’ abilities to conduct interferometry experiments. With the enhanced stability, the team can go months at a time without anything more than slight alterations to the experiment, consistency LeDesma and Mehling hope to leverage as they continue to explore the potential of their sensor.

Skeptics Emerge

While combining AI’s machine learning processes with the sensitivity of quantum mechanics could produce the next generation of quantum sensors, not all are convinced by the results of these experiments.

The standard point of view is that if a scientist wants to measure things precisely, they will want their atoms in the dark and not interacting with anything, a notion popularized by the 1989 Nobel Prize winner Norman Ramsey in his method of separated oscillatory fields.

But here in the lab, the atoms always see the light crystal that they move in, and so the environment must be perfectly controlled. As upgrades to the experimental system are installed and the team continues to report improved performance metrics, Mehling believes more experimenters will be willing to adopt some of their strategy and design philosophies.

In March of 2024, Holland presented the accelerometry results from the one-dimensional and two-dimensional experiments for the first time at a ��Ҵ�ý�ƽ�� Physics Department Colloquium. For both LeDesma and Mehling, the feeling was one of validation.

“We finally had some significant results to show that this thing actually worked,” Mehling says. “After the talk, people came up and asked questions. Later, more people visited the lab, wanting to understand what we were doing. We have been very isolated in Duane, and it’s nice to feel that way no longer.”

Moving Towards Greater Sensitivity

Now, with an improved setup, a NASA grant, and possible future collaborations with other JILA researchers, LeDesma and Mehling are interested in pushing the boundaries of their apparatus as much as possible.

“We want to turn this into a precision measurement experiment,” Mehling adds. “Currently, it’s not as sensitive as we need. We have an end-user for our experiment, goals, and a timetable to keep progress moving sustainably.”

With its versatile design, the researchers have proposed that the apparatus can potentially measure various phenomena, from Earth’s gravity and tidal distribution to the detection of dark matter.

“The realization of the fact that matter can behave as waves and interfere constructively and destructively lies right at the core of the development of quantum mechanics more than one hundred years ago,” explains Holland. “And so, atom optics systems are very fundamental, and to show that we can control them exquisitely with modern machine learning and optimization methods introduces a disruptive solution to a very old technology. We think this experiment is now placed to have a bright future—full of potential—and we don’t know at this point how far we will be able to take it.”

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Twisting and Binding Matter Waves with Photons in a Cavity

Steven Burrows — Sun, 28 Apr 2024 17:14:52 +0000

Twisting and Binding Matter Waves with Photons in a Cavity Steven Burrows Sun, 04/28/2024 - 11:14

Kenna Hughes-Castleberry / JILA Science Communicator

Atoms inside of an optical cavity exchange their momentum states by "playing catch" with photons. As the atoms absorb photons from an applied laser, the whole cloud of atoms recoil rather than the individual atoms. Image credit: Steven Burrows / JILA

Precisely measuring the energy states of individual atoms has been a historical challenge for physicists due to atomic recoil. When an atom interacts with a photon, the atom “recoils” in the opposite direction, making it difficult to measure the position and momentum of the atom precisely. This recoil can have big implications for quantum sensing, which detects minute changes in parameters, for example, using changes in gravitational waves to determine the shape of the Earth or even detect dark matter.

In a new paper published in Science, JILA and NIST Fellows Ana Maria Rey and James Thompson, JILA Fellow Murray Holland, and their teams proposed a way to overcome this atomic recoil by demonstrating a new type of atomic interaction called momentum-exchange interaction, where atoms exchanged their momentums by exchanging corresponding photons.

Using a cavity—an enclosed space composed of mirrors—the researchers observed that the atomic recoil was dampened by atoms exchanging energy states within the confined space. This process created a collective absorption of energy and dispersed the recoil among the entire population of particles.

With these results, other researchers can design cavities to dampen recoil and other outside effects in a wide range of experiments, which can help physicists better understand complex systems or discover new aspects of quantum physics. An improved cavity design could also enable more precise simulations of superconductivity, such as in the case of the Bose-Einstein-Condensate-Bardeen-Cooper-Schrift (BEC-BCS) crossover or high-energy physical systems.

For the first time, the momentum-exchange interaction was observed to induce one-axis twisting (OAT) dynamics, an aspect of quantum entanglement, between atomic momentum states. OAT acts like a quantum braid for entangling different molecules, as each quantum state gets twisted and connected to another particle.

Previously, OAT was only seen in atomic internal states, but now, with these new results, it is thought that OAT induced by momentum exchange could help reduce quantum noise from multiple atoms. Being able to entangle momentum states could also lead to improvement in some physical measurements by quantum sensors, such as gravitational waves.

Leveraging a Density Grating

Within this new study, inspired by previous research from Thompson and his team, the researchers examined the effects of quantum superposition, which allows particles like photons or electrons to exist in multiple quantum states simultaneously.

“In this [new] project, the atoms all share the same spinlabel; the only difference is that each atom is in a superposition between two momentum states,” graduate student and first author Chengyi Luo explained.

The researchers found they could better control atomic recoil by forcing the atoms to exchange photons and their associated energies. Similar to a game of dodgeball, one atom may “throw” a “dodgeball” (a photon) and recoil in the opposite direction. That “dodgeball” may be caught by a second atom, which can cause the same amount of recoil for this second atom. This cancels out the two recoils experienced by both atoms and averages them for the entire cavity system.

When two atoms exchange their different photon energies, the resulting wave packet (an atom’s wave distribution) in superposition forms a momentum graph known as a density grating, which looks like a fine-toothed comb.

Luo added. “The formation of the density grating indicates two momentum states [within the atom] are ‘coherent’ with each other such that they could interfere [with each other].” The researchers found that the exchange of photons between atoms caused a binding of the two atoms’ wave packets, so they were no longer separate measurements.

The researchers could induce momentum exchange by exploring the interplay between the density grating and the optical cavity. Because the atoms exchanged energy, any recoil from absorbing a photon was dispersed among the entire community of atoms instead of individual particles.

Dampening the Doppler Shift

Using this new control method, the researchers found that they could also use this recoil-dampening system to help mitigate a separate measurement problem: the Doppler shift.

The Doppler shift, a phenomenon in classical physics, explains why the sound of a siren or train horn changes pitch as it passes a listener or why certain stars appear red or blue in night sky images—it’s the change in the frequency of the wave as the source and observer move toward (or away from) each other. In quantum physics, the Doppler shift describes a particle’s energy change due to relative motion.

For researchers like Luo, the Doppler shift can be a challenge to overcome in getting a precise measurement. “When absorbing photons, the atomic recoil will lead to a Doppler shift of the frequency of the photon, which is a big problem when you talk about precision spectroscopy,” he elaborated. By simulating their new method, the researchers found that it could overcome measurement skewing due to Doppler Shift.

Entangling Momentum Exchange

The researchers also found that the momentum exchange between these atoms could be used as a type of quantum entanglement. As John Wilson, a graduate student in the Holland group, elaborated: “As an atom falls, its motion wiggles the cavity frequency. That, in turn, encourages other atoms to collectively feel that feedback mechanism and nudges them to correlate their motion through the shared wobbles.”

To test this “entanglement” even further, the researchers created a bigger separation between the momentum states of the atoms and then induced the momentum exchange. The researchers found that the atoms continued to behave as if they were connected. “This indicates that the two momentum states are really oscillating concerning each other as if being connected by a spring,” added Luo.

Looking ahead, the researchers plan to probe this new form of quantum entanglement further, hoping to better understand how it can be used to improve various types of quantum devices.

This research was supported by the US Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Systems Accelerator.

In a new paper published in Science, JILA and NIST Fellows Ana Maria Rey and James Thompson, JILA Fellow Murray Holland, and their teams proposed a way to overcome atomic recoil by demonstrating a new type of atomic interaction called momentum-exchange interaction, where atoms exchanged their momentums by exchanging corresponding photons.

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JILA Fellow Murray Holland awarded a Translational Quantum Research Seed Grant Administered by ��Ҵ�ý�ƽ��

Steven Burrows — Tue, 23 Jan 2024 18:48:14 +0000

JILA Fellow Murray Holland awarded a Translational Quantum Research Seed Grant Administered by ��Ҵ�ý�ƽ�� Steven Burrows Tue, 01/23/2024 - 11:48

Kenna Hughes-Castleberry / JILA Science Communicator

��Ҵ�ý�ƽ�� has proudly announced the winners of its prestigious 2023-2024 Translational Quantum Research Seed Grants, a crucial step in fostering quantum science and technology innovation. This year's selection includes JILA Fellow Murray Holland, a distinguished figure in the field of quantum physics, who has been recognized for his groundbreaking project, "Developing a strontium optical lattice atom interferometer."

Holland's work at ��Ҵ�ý�ƽ��'s Department of Physics is among the three university-led projects to be honored, alongside four commercial enterprise-led initiatives. These grants, each amounting to $50,000 and spanning an 18-month period, are designed to bridge the gap between laboratory research and commercial viability, emphasizing the importance of translating academic discoveries into real-world applications.

The award of these grants follows the April 2023 decision by the Colorado Economic Development Commission to allocate nearly $1.5 million toward integrating basic and applied quantum research with Colorado’s burgeoning startup ecosystem. This initiative also aims to provide Colorado students with effective pathways into the quantum workforce.

Eve Lieberman, Executive Director of the Colorado Office of Economic Development and International Trade, emphasized the state’s commitment to quantum innovation. "These seed grants are a critical step in linking laboratory discoveries to the commercial sector, reinforcing Colorado's position as a frontrunner in this revolutionary field," she said.

The grants are part of Colorado’s ongoing investment in quantum science and technology, a field in which the region has already achieved global recognition, partly due to the foundational work of institutions like ��Ҵ�ý�ƽ��, NIST, and JILA. With four Nobel Prizes in physics awarded to affiliated quantum researchers, the Boulder triad has been instrumental in shaping the global quantum landscape.

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Making Use of Quantum Entanglement

Steven Burrows — Fri, 03 Nov 2023 17:09:35 +0000

Making Use of Quantum Entanglement Steven Burrows Fri, 11/03/2023 - 11:09

Kenna Hughes-Castleberry / JILA Science Communicator

Visualization of locating the optimal generator on a Bloch sphere. The color represents the QFI for the given generator. Image credit: Steven Burrows / JILA

Quantum sensors help physicists understand the world better by measuring time passage, gravity fluctuations, and other effects at the tiniest scales. For example, one quantum sensor, the LIGO gravitational wave detector, uses quantum entanglement (or the interdependence of quantum states between particles) within a laser beam to detect distance changes in gravitational waves up to one thousand times smaller than the width of a proton!

LIGO isn’t the only quantum sensor harnessing the power of quantum entanglement. This is because entangled particles are generally more sensitive to specific parameters, giving more accurate measurements.

While researchers can generate entanglement between particles, the entanglement may only be useful sometimes for sensing something of interest. To measure the “usefulness” of quantum entanglement for quantum sensing, physicists calculate a mathematical value, known as the Quantum Fisher Information (QFI), for their system. However, physicists have found that the more quantum states in the system, the harder it becomes to determine which QFI to calculate for each state.

To overcome this challenge, JILA Fellow Murray Holland and his research team proposed an algorithm that uses the Quantum Fisher Information Matrix (QFIM), a set of mathematical values that can determine the usefulness of entangled states in a complicated system.

Their results, published in Physical Review Letters as an Editor’s Suggestion, could offer significant benefits in developing the next generation of quantum sensors by acting as a type of “shortcut” to find the best measurements without needing a complicated model.

“Being able to lay out a roadmap that allows you to understand the usefulness of entanglement in higher-level systems is a fundamental solution in quantum information science,” said Holland.

Looking at Multiple Dimensions

Most theoretical physicists researching quantum information science (which includes quantum sensing) focus on a system known as a qubit or “quantum bit,” graphically represented by a Bloch sphere or a 3D visual representation of all possible states of a qubit. A qubit is considered an SU(2) system where SU(n) is a simple way to mathematically describe how things in the quantum world can change and interact by exploiting the system’s symmetry. A qubit is considered an SU(2) system as it has a symmetry between two quantum levels, but as the number of levels go up, so does the SU(n).

Because these SU(n) systems can describe quantum entanglement, things get complicated quickly when n increases, as the system can exhibit multiple dimensions or ways that properties like entanglement can change in a multi-state system.

“You can think of the SU(n) system as putting a bunch of dots on a piece of paper and drawing a red, blue, and green line between these dots,” explained Jarrod Reilly, one of the paper’s first co-author and a graduate student in Holland’s group. The dots represent the different quantum states, while the lines highlight how the states “interact” with each other.

Instead of studying the SU(2) system with two distinct states (also known as degrees of freedom), Holland and his team looked at the SU(4) system, which describes four independent states. When studying the SU(4) setup, the researchers realized they were dealing with a mind-boggling 15 dimensions for how entanglement and other properties could change in the system!
Quickly, the team understood that a simple brute force calculation for the best use of the SU(4) system’s entanglement would be nearly impossible. “We had these states in this four-level system that were super complicated; we had no way of visualizing it,” elaborated John Wilson, a graduate student in the Holland group and the paper’s other first co-author.

To make it easier to calculate the QFI for these 15 dimensions, the researchers created an algorithm utilizing the QFIM, resulting in the best possible QFI value for the system. “We've come up with a method using the Quantum Fisher Information Matrix which says, here is the set of quantities for a given complicated state; these are the quantities that the state carries the most [useful] information about,” added Wilson.

Mathematical Shortcuts to Usefulness

Thanks to this algorithm, scientists have a type of “shortcut” that can give them the values of usefulness for more complicated systems without having to entangle them experimentally.
“If you have an experiment with complicated physics, you don’t need a full model to pull out how entanglement in the sensor could be used.” elaborated Holland. “To test if it's a good sensor, you only need to know the underlying symmetries of what you want to sense.”

The other benefit of this new algorithm is that it can work on almost any complicated quantum setup, making it useful for physicists in advancing current levels of quantum sensing technology.
Reilly elaborated that the algorithm works as an optimization problem. As an illustration, Reilly explained that if you were hypothetically trying to find the steepest part of a hill—which Reilly highlighted could have 15 dimensions—to roll a ball down, you could use the algorithm to calculate this solution without checking each direction.

“The algorithm leverages an underlying connection between quantum information (via entanglement) and geometrical concepts from Einstein's theory of relativity, two pinnacle fields of physics that rarely interact in research,” Reilly added.

While previous research has looked at measuring the QFI of quantum entanglement from a state-first perspective (where the sensor was created first, and then the entanglement was generated), this paper is one of the first to take the opposite approach.

“We can generate these classes of states, so we ask ourselves, what could we build with it?” Holland added. “It’s a new approach to understanding this whole sensing domain and a compelling method for quantum metrology.”

JILA Fellow Murray Holland and his research team proposed an algorithm that uses the Quantum Fisher Information Matrix (QFIM), a set of mathematical values that can determine the usefulness of entangled states in a complicated system.

Their results, published in Physical Review Letters as an Editor’s Suggestion, could offer significant benefits in developing the next generation of quantum sensors by acting as a type of “shortcut” to find the best measurements without needing a complicated model.

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JILA Researcher Jarrod Reilly highlighted in a New “Physics Magazine” Article

Steven Burrows — Thu, 12 Oct 2023 18:20:31 +0000

JILA Researcher Jarrod Reilly highlighted in a New “Physics Magazine” Article Steven Burrows Thu, 10/12/2023 - 12:20

Kenna Hughes-Castleberry / JILA Science Communicator

Visualization of locating the optimal generator on a Bloch sphere. The color represents the QFI for the given generator. Image credit: Steven Burrows / JILA

Leading the way in quantum sensing advancements, JILA, a renowned institute at the forefront of quantum sensing research, has once again proven its prowess. In a new Physics Magazine article, JILA graduate student Jarrod Reilly was highlighted in his work developing a groundbreaking approach that promises to redefine the capabilities of quantum sensors.

Quantum sensors, which employ phenomena like entangled states of light, have been instrumental in applications such as the LIGO gravitational wave detector. This detector harnesses these entangled states to detect minuscule distance changes in gravitational waves.

According to the Physics Magazine article: “Typically, quantum sensors use systems prepared in special quantum states known as probe states. Finding the ideal probe state for a given measurement is a focus of many research endeavors. Now Jarrod Reilly of the University of Colorado Boulder and his colleagues have developed a new framework for optimizing this search. The approach could aid in developing quantum sensors that surpass the standard quantum limit—the minimum noise level of a device that can be obtained without special quantum-state preparation—and so could dramatically increase measurement sensitivity.”

Reilly, along with JILA graduate student John Wilson and JILA Fellow Murray Holland, who is also a ��Ҵ�ý�ƽ�� physics professor, were inspired by classical physics to develop their new method. The team’s approach discerns various changes in a quantum system using a mathematical algorithm, thereby determining its sensitivity to specific parameters. Such advancements not only promise to refine existing quantum sensors but also hold the potential for quantum sensors to estimate multiple parameters simultaneously, a requirement in many imaging and metrology applications.

The article continues: “The method of Reilly and his colleagues flips that search protocol on its head.” The team published their results recently in Physical Review Letters.

Given the revolutionary perspective brought forward by the JILA team, emphasizing high-precision measurements, the quantum technology landscape seems poised for significant advancements and a deeper understanding of quantum mechanics in the coming years.

Leading the way in quantum sensing advancements, JILA, a renowned institute at the forefront of quantum sensing research, has once again proven its prowess. In a new Physics Magazine article, JILA graduate student Jarrod Reilly was highlighted in his work developing a groundbreaking approach that promises to redefine the capabilities of quantum sensors.

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NASA Awards Grant to Group of Quantum Institutes Including JILA and the University of Colorado Boulder for Researching Quantum in Space

Steven Burrows — Thu, 16 Mar 2023 17:39:45 +0000

NASA Awards Grant to Group of Quantum Institutes Including JILA and the University of Colorado Boulder for Researching Quantum in Space Steven Burrows Thu, 03/16/2023 - 11:39

Kenna Hughes-Castleberry / JILA Science Communicator

From left to right: Murray Holland, (front) Catie Ledesma, (back) Kendall Mehling, (Front) Liang-Ying (former JILA graduate student), and Dana Anderson

JILA (a world-leading physics research institute set up by NIST and the University of Colorado Boulder) is part of a multi-university research group that will build quantum-based tools for space-based Earth sensing. NASA expects to award a $15 million grant for five years to the group of universities. This cohort includes researchers from the University of Texas at Austin, JILA, the University of Colorado Boulder (CU), the University of California Santa Barbara (USCB), the California Institute of Technology (Caltech), and the U.S. National Institute for Standards and Technology (NIST). “The award establishes the Quantum Pathways Institute, supported by a NASA STRI (Space Technology Research Institute), led by Prof. Srinivas Bettadpur of the University of Texas at Austin, Texas, with CU and UCSB as collaborating institutions,” explained Dana Anderson, a JILA Fellow and ��Ҵ�ý�ƽ�� professor who is involved in the project. The Quantum Pathways Institute is the first of its kind, as it strives to translate the capabilities of quantum physics into usable devices called “Quantum 2.0.” Besides these developments, the Institute will offer educational training for graduate students and postdocs in quantum theory and quantum experimentation.

The project “will focus on the concept of quantum sensing, which involves observing how atoms react to small changes in their environment and using that to infer the time-variations in the Earth’s gravity field,” explained University of Texas communicator Nat Levy in a recent announcement. “This will enable scientists to improve how accurately several important climate processes can be measured, such as the sea level rise, the rate of ice melt, the changes in land water resources, and ocean heat storage changes.”

For JILA’s part, JILA Fellows Murray Holland and Dana Anderson are working with the University of Colorado researchers Penny Axelrad, Marco Nicotra, and NIST researcher Michelle Stephens. “JILA’s contribution reflects its long history in precision measurement, AMO, and quantum physics,” explained Holland. “In collaboration with the ECEE and Aerospace departments here, recent efforts have combined JILA’s quantum science expertise with modern machine learning and control methods to create high fidelity shaken optical lattice quantum sensors. Work here and elsewhere has demonstrated the potential of these methods for optimizing the design and control of quantum sensors beyond what any human has achieved to date.”

Research within the Quantum Pathways Institute will focus on developing precise quantum-based instruments specifically targeting gravity gradiometry. “Our effort builds on the well-known JILA optical lattice clock technology using ultracold atoms, but here applied to extreme inertial sensing capabilities rather than time-keeping,” Holland elaborated. Anderson added: “CU’s role is to develop the sensor including the associated hardware and systems, as well as an associated testbed, to be housed within JILA. In conjunction with the hardware is developing the optimal control and machine learning algorithms to optimize sensor characteristics.”

The shaken optical lattice gravity gradiometer will be designed to produce precise measurements critical for monitoring climate changes. “As climate shifts – with ice caps melting and sea levels and temperatures changing – that changes gravitational forces around the earth and in outer space,” Levy stated in the University of Texas announcement. “Atoms orbiting the earth respond to those gravitational changes. By measuring those reactions, the researchers can give better readings of changes in climate processes.”

The awarding of this grant will further expand JILA’s and ��Ҵ�ý�ƽ�� reputations as world-leading institutes for quantum physics research. Other organizations within these systems, such as the CUbit Quantum Initiative, also help enrich this ecosystem and offer exclusive opportunities to push the frontiers of quantum physics.

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Murray Holland

An Atomic Clock That Stays Cool and Can Rock and Roll Without Losing Time

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JILA Joins DOE’s Quantum Systems Accelerator for Next Phase of Quantum Innovation

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New quantum navigation device uses atoms to measure acceleration in 3D

Fingerprints of motion

Planning with computers

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Combining Machine Learning with Quantum Metrology: Making a Universal Quantum Sensor

Following JILA’s Legacy of Laser Stability

Adding Machine Learning

Validating Their Setup

Creating Versatile Quantum Sensors

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Meet the JILA Postdoc and Graduate Student Leading the Charge in a Multi-Million-Dollar NASA-Funded Quantum Sensing Project

Taking the Quantum Reins

Engineering Your Own Quantum Sensor

Adding AI to Quantum

NASA Buys In

Rebuilding a Laboratory in Seven Days

Skeptics Emerge

Moving Towards Greater Sensitivity

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Twisting and Binding Matter Waves with Photons in a Cavity

Leveraging a Density Grating

Dampening the Doppler Shift

Entangling Momentum Exchange

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JILA Fellow Murray Holland awarded a Translational Quantum Research Seed Grant Administered by ���Ҵ�ý�ƽ������

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Making Use of Quantum Entanglement

Looking at Multiple Dimensions

Mathematical Shortcuts to Usefulness

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JILA Researcher Jarrod Reilly highlighted in a New “Physics Magazine” Article

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NASA Awards Grant to Group of Quantum Institutes Including JILA and the University of Colorado Boulder for Researching Quantum in Space

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JILA Fellow Murray Holland awarded a Translational Quantum Research Seed Grant Administered by ��Ҵ�ý�ƽ��