Henry Kapteyn
This year, JILA celebrates its 60th anniversary. Officially established on April 13, 1962, as a joint institution between the University of Colorado Boulder and the National Institute of Standards and Technology (NIST), JILA has become a world leader in physics research. Its rich history includes three Nobel laureates, groundbreaking work in laser development, atomic clocks, underlying dedication to precision measurement, and even competitive sports leagues. The process of creating this science goliath was not always straightforward and took the dedication and hard work of many individuals.
More than 400 years later, scientists are in the midst of an equally-important revolution. They鈥檙e diving into a previously-hidden realm鈥攆ar wilder than anything van Leeuwenhoek, known as the 鈥渇ather of microbiology,鈥 could have imagined. Some researchers, like physicists Margaret Murnane and Henry Kapteyn, are exploring this world of even tinier things with microscopes that are many times more precise than the Dutch scientist鈥檚. Others, like Jun Ye, are using lasers to cool clouds of atoms to just a millionth of a degree above absolute zero with the goal of collecting better measurements of natural phenomena.
Physicists develop some of the most cutting-edge technologies, including new types of lasers, microscopes, and telescopes. Using lasers, physicists can learn more about quantum interactions in materials and molecules by taking snapshots of the fastest processes, and many other things. While lasers have been used for decades, their applications in technology continue to evolve. One such application is to generate and control x-ray laser light sources, which produce much shorter wavelengths than visible light. This is important because progress in developing x-ray lasers with practical applications had essentially stalled for over 50 years. Fortunately, researchers are beginning to change this by using new approaches. In a paper published in Science Advances, a JILA team, including JILA Fellows Margaret Murnane, and Henry Kapteyn, manipulated laser beam shapes to better control properties of x-ray light.
Two new papers from the Murnane and Kapteyn group are changing the way heat transport is viewed on a nanoscale, and explain the group鈥檚 surprising finding that nanoscale heat transport can be far more efficient than originally thought. One of these papers, published in the Proceedings of the National Academy of Sciences (PNAS), explains heat transport for the tiniest of hotspots, with sizes <100 nm. The other, published in American Chemical Society Nano (ACS Nano), presents a theory that is applicable to larger arrays of hotspots. Both papers postulate theories that can fully explain the surprising data collected by the team of researchers, showing that heat transport on scale lengths relevant to a wide range of nanotechnologies is more efficient than originally thought.
The National Science Foundation has renewed for five years and more than $22 million the cutting-edge Science and Technology Center on Real-Time Functional Imaging (STROBE). STROBE is developing the Microscopes of Tomorrow, and is a partnership between six institutions 鈥撯 University of Colorado Boulder, UCLA, UC Berkeley, Florida International University, Fort Lewis College, and UC Irvine.
For laser science, one major goal is to achieve full control over the spatial, temporal and polarization properties of light, and to learn how to precisely manipulate these properties. A property of light is called the Orbital Angular Momentum (OAM), that depends on the spatial distribution of the phase (or crests) of a doughnut-shaped light beam. More recently, a new variant of OAM was discovered - called the spatial-temporal OAM (ST-OAM), with much more elusive properties, since the phase/crests of light evolve both temporally and spatially. In a collaboration led by senior scientist Dr. Chen-Ting Liao, working with graduate student Guan Gui and Nathan Brooks and JILA Fellows Margaret Murnane and Henry Kapteyn, the team explored how such beams change after propagating through nonlinear crystals that can change their color. The team published theri results in聽Nature Photonics.
Margaret Murnane and Henry Kapteyn, who pioneered technologies for generating coherent X-rays, which helped propel research in dynamic processes in atoms, molecules and materials, have been named fellows of the National Academy of Inventors.
All atoms, molecules and materials are held together by a web of interactions between electrons and ions. In materials, tiny vibrations called phonons cause the positions of the ions to oscillate. How those phonons and electrons are coupled鈥攐r interact鈥攄etermines a material鈥檚 properties. The Kapetyn-Murnane Group found that by using ultrafast laser pulses to excite the material, they can precisely study the interaction between electrons and the most important phonons in tantalum diselenide (1T-TaSe2)鈥攁nd also manipulate it.
Margaret Murnane and Henry Kapteyn are the third married couple to win the coveted award from The Franklin Institute.
By using ultrafast lasers to measure the temperature of electrons, JILA researchers have discovered a never-before-seen state in an otherwise standard semiconductor. This research is the most recent demonstration of a new technique, called ultrafast electron calorimetry, which uses light to manipulate well-known materials in new ways.