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.

Research Areas

  • 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).

  • Although x-ray imaging has been explored for decades, and visible-wavelength microscopy for centuries, it is only recently that the spectral region in between―the extreme ultraviolet (EUV)―has been explored for imaging nanostructures and nanomaterials.

  • 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.

  • Nanoparticles exhibit a surface-area-to-volume ratio many orders of magnitude higher than bulk materials, allowing them to serve as powerful catalysts for chemical reactions, both in the laboratory and as atmospheric aerosols.

  • 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

Senator Hickenlooper (center) talks to JILA's instrument shop head Kyle Thatcher (left) and JILA instrument maker Hans Green (right).
December 18, 2023: Senator Hickenlooper Discusses Quantum Computing's Role in Boosting Colorado's Economy at Latest JILA Visit

In a recent significant visit to JILA, a joint institute established by the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder, U.S. Senator John Hickenlooper discussed the transformative potential of quantum computing on Colorado's economy, job industry, and educational sector. The visit underscored the state's growing prominence in the quantum technology landscape.

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JILA graduate student Nick Jenkins adjusts a setting on his laser tabletop setup.
December 14, 2023: JILA Graduate Student Nick Jenkins Wins Prestigious Nick Cobb Memorial Scholarship

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.

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JILA graduate student Daniel Carlson
October 25, 2023: JILA Graduate Student Daniel Carlson awarded Best Paper Award at Optica International Conference on Advanced Solid State Lasers

To honor students' abilities for clear and effective communication in quantum physics, Optica offers a yearly "best paper" award at its International Conference on Advanced Solid State Lasers. This year, JILA graduate student Daniel Carlson was among the list of winners, with his presentation "Carbon K-Edge Soft X-Rays Driven by a 3 µm,1 kHz OPCPA Laser System" winning over the judges. 

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JILA graduate student Jeremy Thurston
October 25, 2023: JILA Graduate Student Jeremy Thurston Given Awarded Prize for Emil Wolf Outstanding Student Paper Competition

Every year, the Frontiers in Optics conference holds the Emil Wolf Outstanding Student Paper Competition, acknowledging the excellence of students in presenting their work at the conference in both paper and poster form. This year, JILA graduate student Jeremy Thurston of the Murnane and Kapteyn research groups showcased his work in both a paper and presentation titled: "Bright Tunable Ultrafast Deep- and Vacuum-Ultraviolet Harmonic Combs," which was awarded a prize by the judges for excellence in communication. 


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JILA Address

We are located at JILA: A joint institute of NIST and the University of Colorado Boulder.

Map | JILA Phone: 303-492-7789 | Address: 440 UCB, Boulder, CO 80309