Margaret Murnane
Two new papers from the Murnane and Kapteyn group are changing the way heat transport is viewed on a nanoscale, and explain the group’s 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 –– 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 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.
Nanoscale materials act differently than their macro counterparts. Using ultra-fast extreme ultraviolet lasers, the KM Goup at JILA has been able to probe silicon carbide as thin as 5 nanometers to understand its strength as it shrinks. This research will help engineers designing ever-shrinking electronics and other technologies.
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—or interact—determines a material’s 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)—and 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.
JILA Fellow Margaret Murnane was one of 10 recipients of the Presidential Distinguished Service Award for the Irish Abroad. Tánaiste and Minister for Foreign Affairs Simon Coveney announced the names of the award winners on the 28th of November 2018. These awards, established in 2012, are meant to recognize the contributions of members of the Irish diaspora.
CO-LABS presented JILA’s ultrafast imaging team, led by Fellows Margaret Murnane and Henry Kapteyn, the 2018 Governor’s Award for High-Impact Research. Murnane and Kapteyn were honored for their work in revolutionizing ultrafast and nanoscale imaging through the research and development of tabletop x-ray sources. These advancements enable real-time imaging of the structure, chemistry, and dynamics of materials at the level of small collections of atoms. The applications range from improving semiconductor devices and magnetic storage to understanding the fundamental physics and chemistry of complex materials. By designing, developing, and eventually enabling the availability of this technology through KM-Labs, Murnane and Kapteyn have enabled many curious researchers to further their discoveries.