About the Kapteyn-Murnane Group
Our group is developing new probes of quantum matter using coherent X-ray beams, which have undergone a revolution in the past decade. More than 50 years after the demonstration of the visible laser, it is finally possible to generate laser-like beams spanning the deep-UV, extreme ultraviolet (EUV) and soft X-ray regions of the spectrum by harnessing high harmonic upconversion of femtosecond lasers. Moreover, by combining phase matching techniques and selection rules, we can achieve exquisite “quantum” control over x-ray light. It is now possible to produce short wavelength waveforms with controlled spectral and temporal shapes, polarization state, and phase structure. Exciting recent advances also include the first sub-wavelength imaging at short wavelengths, the ability to directly manipulate spins in materials using light, the first methods to measure the full mechanical properties of ultrathin films and nanostructured media, uncovering new regimes of nanoscale heat flow, as well as routes for mapping new states and phases in quantum materials. Ultrafast coherent EUV and x-ray beams are thus becoming indispensable tools in the race to develop new nanoscale and quantum devices.
We welcome trainees from physics, materials science, engineering and chemistry to work together to solve grand-challenge scientific problems that are also at the technological forefront. Trainees from our group go on to positions in academe, industry and national laboratories.
Ever since the invention of the visible laser over 50 years ago, scientists have been striving to create lasers that generate coherent beams at shorter wavelengths i.e. the extreme UV (EUV) and soft X-ray (SXR) regions of the spectrum. This quest has led to the construction of large facilities, such as kilometer-scale x-ray free-electron lasers, to reach the keV photon energy region.
Magnetism has been the subject of scientific inquiry for more than 2000 years. However, it is still an incompletely understood phenomenon. The fundamental length and time scales for magnetic phenomena range from Å (exchange lengths) and sub-femtoseconds (exchange splitting) on up.
High harmonics are ideal as the illumination source for time- and angle-resolved photoemission spectroscopy (trARPES), which can measure the full electronic band structure of a material. Moreover, a new generation of ultrafast (~50-100fs), MHz rep rate, VUV (1-20eV) highly-cascaded high harmonics driven by compact fiber lasers have 10-100meV energy resolution, and are ideal for spin-resolved ARPES (Optica 7, 832 (2020).
Heat transport is driven by a thermal gradient, flowing from hot to cold regions in a material. However, at dimensions <100nm, bulk models no longer accurately predict the transport properties of materials. Because no complete models of nanoscale heat transport were available, it was assumed instead that bulk-like diffusive heat transport was valid—provided that an effective parameter, such as a size-dependent thermal conductivity, was incorporated.
The demand for faster, more efficient, and more compact nanoelectronic devices, like smartphone chips, requires engineers to develop increasingly complex designs. To achieve this, engineers use layer upon layer of very thin films – as thin as only a couple strands of DNA – with impurities added, to tailor the function.
Science and technology are inextricably linked and continue to drive each other. Ultrafast lasers have revolutionized our understanding of how molecules and materials work and how charges, spins, phonons and photons interact dynamically. In past research, our group designed Ti:sapphire lasers that operate at the limits of pulse duration and stability, with adjustable pulse durations from 7 fs on up.
In the Spotlight
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.
Congratulations to Giulia Mancini for receiving the IUPAP Young Scientist Prize in Optics! In 2005 the International Union of Pure and Applied Physics (IUPAP) created the Young Scientist Prizes for its commissions. The international Commission of Optics (ICO), as an Affiliated Commission of IUPAP, decided in 2008 to adopt the IUPAP Young Scientist Prize in Optics. The IUPAP prize in optics will be awarded annually through ICO to a scientist who has made noteworthy contributions to applied optics and photonics during a maximum of 8 years of research experience after having earned a PhD degree. Career interruptions will not be counted as time of research experience.
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.
The NIST NRC Postdoctoral Program supports a nationwide competitive postdoctoral program administered in cooperation with the National Academies/National Research Council (NRC). The postdoctoral program brings research scientists and engineers of unusual promise and ability to perform advanced research related to the NIST mission, introduces the latest university research results and techniques to NIST scientific programs, strengthens mutual communication with university researchers, shares NIST unique research facilities with the U.S. scientific and engineering communities, and provides a valuable mechanism for the transfer of research results from NIST to the scientific and engineering communities.