Nanoscience
Drum-like membrane resonators are intriguing for precision sensing because their resonance frequencies can be sensitive to a variety of parameters of interest, from mass to thermal radiation. The quest for improved sensitivity in tensioned membranes faces a tradeoff in which a high amplitude of mechanical motion improves signal-to-noise, but too high of a drive (beyond the so-called critical amplitude) introduces nonlinear effects.
In our work published in NanoLetters, we develop an experimentally straightforward method to evade this tradeoff. Using a patterned, trampoline-shaped membrane, we find that dual-mechanical-mode operation can bring these sensors to a thermally-limited frequency stability.听 By measuring and correcting for frequency noise arising at high amplitude, we maintain this high stability when operating beyond the linear regime, opening new opportunities for membrane frequency sensing.
Physicists at 蜜桃传媒破解版下载 have demonstrated a new kind of vacuum ultraviolet laser that could one day allow scientists to observe phenomena currently out of reach for the most powerful microscopes.
The new laser could allow researchers to follow fuel molecules in real time as they undergo combustion, spot incredibly small defects in nanoelectronics, track time with unprecedented precision and more.
The JILA team will present its preliminary findings on March 17 and March 19 at the American Physical Society Global Physics Summit in Denver.
A team led by JILA Fellows and 蜜桃传媒破解版下载 professors Margaret Murnane and Henry Kapteyn has made a significant advance to make soft X-rays more accessible: with their research group, they have developed an ultrastable, scalable and repeatable method for generating soft X-ray beams using a custom-built 3-micron ultrafast laser that is focused into an anti-resonant hollow-core fiber.
Researchers at JILA have developed a novel microscope that makes examining ultrawide-bandgap semiconductors possible on an unprecedented scale. The team鈥檚 work, recently published in Physical Review Applied, introduces a tabletop deep-ultraviolet (DUV) laser that can excite and probe nanoscale transport behaviors in materials such as diamond. This microscope uses high-energy DUV laser light to create a nanoscale interference pattern on a material鈥檚 surface, heating it in a controlled, periodic pattern. Observing how this pattern fades over time provides insights into the electronic, thermal, and mechanical properties at spatial resolutions as fine as 287 nanometers, well below the wavelength of visible light.
On June 20, 2024, the U.S. National Science Foundation awarded JILA and the University of Colorado Boulder a $20 million grant to create the听National Quantum Nanofab (NQN), a cutting-edge facility poised to revolutionize quantum technology.
JILA Fellow and University of Colorado Boulder physics professor Cindy Regal remarked, "The NQN will be a unique facility for quantum discoveries and technology. I look forward to seeing the NQN as a national resource in quantum and interfacing with a wide range of JILA research.鈥
Nick Jenkins, a graduate student at JILA, an institute jointly operated by the University of Colorado Boulder and the National Institute of Standards and Technology (NIST), has been awarded the esteemed Nick Cobb Memorial Scholarship. Mentored by JILA Fellows and University of Colorado Boulder professors Margaret Murnane and Henry Kapteyn, Jenkins' research focuses on pioneering tabletop extreme ultraviolet (EUV) microscopy techniques using high-harmonic generation light sources. This innovative work has positioned him as a standout recipient of this significant award.
As reported in a new Science Advances paper, the JILA team and collaborators from universities in Sweden, Greece, and Germany probed the spin dynamics within a special material known as a Heusler compound: a mixture of metals that behaves like a single magnetic material. For this study, the researchers utilized a compound of cobalt, manganese, and gallium, which behaved as a conductor for electrons whose spins were aligned upwards and as an insulator for electrons whose spins were aligned downwards.
In quantum information science, many particles can act as 鈥渂its,鈥 from individual atoms to photons. At JILA, researchers utilize these bits as 鈥渜ubits,鈥 storing and processing quantum 1s or 0s through a unique system.
While many JILA Fellows focus on qubits found in nature, such as atoms and ions, JILA Associate Fellow and University of Colorado Boulder Assistant Professor of Physics Shuo Sun is taking a different approach by using 鈥渁rtificial atoms,鈥 or semiconducting nanocrystals with unique electronic properties. By exploiting the atomic dynamics inside fabricated diamond crystals, physicists like Sun can produce a new type of qubit, known as a 鈥渟olid-state qubit,鈥 or an artificial atom.
In a new ACS Nano paper, JILA and NIST Fellow David Nesbitt, along with former graduate student Jacob Pettine and other collaborators, developed a new method for measuring the dynamics of specific particles known as 鈥渉ot carriers,鈥 as a function of both time and energy, unveiling detailed information that can be used to improve collection efficiencies.
To understand how EDTA binds to metal ions and water molecules, Madison Foreman, a former JILA graduate student in the Weber group, now a postdoctoral researcher at the University of California, Berkeley, Terry, and their supervisor, JILA Fellow J. Mathias Weber, studied the geometry of the EDTA binding site using a unique method that helped to isolate the molecules and their bound ions, allowing for more in-depth analyses of the binding interactions. They published a series of three papers on this topic. In their first paper, published in the Journal of Physical Chemistry A, they found that the size of the metal ion changes where it sits in the EDTA binding site, which affects other binding interactions, especially with water.