The Morris Loeb Lecture in Physics: Margaret Murnane

April 2, 2018
Prof. Murnane photo

The lectures, sponsored by the Morris Loeb Lectureship Fund, are free and open to the public.


Director of the US National Science Foundation STROBE Science and Technology Center on functional nanoimaging Professor of Physics and Electrical and Computer Engineering University of Colorado at Boulder Fellow, JILA

"Harnessing Quantum Light Science for Tabletop X-Ray Lasers, with Applications in Nanoscience and Nanotechnology"

Tuesday, April 10, 2018 @ 2:00pm
Jefferson 250, 17 Oxford Street, Cambridge
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Ever since the invention of the laser over 50 years ago, scientists have been striving to create an X-ray version of the laser. The X-ray sources we currently use in medicine, security screening, and science are in essence the same X-ray light bulb source that Röntgen used in 1895. In the same way that visible lasers can concentrate light energy far better than a light bulb, a directed beam of X-rays would have many useful applications in science and technology. The problem was that until recently, we needed ridiculously high power levels to make an x-ray laser. To make a practical, tabletop-scale, X-ray laser source required taking a very different approach that involves transforming a beam of light from a visible femtosecond laser into a beam of directed X-rays. The story behind how this happened is surprising and beautiful, highlighting how powerful our ability is to manipulate nature at a quantum level. Along the way, we also learned to generate the shortest strobe light in existence - fast enough to capture the fastest attosecond electron dynamics in materials. We also learned how to achieve sub-wavelength spatial resolution at soft X-ray wavelengths for the first time. These new capabilities are already impacting nano and materials science, as well as showing promise for next-generation electronics, data and energy storage devices.

"Capturing the Fastest Charge and Spin Dynamics in Nanosystems using Tabletop High Harmonic Beams"

Wednesday, April 11, 2018 @ 4:00pm
Jefferson 250, 17 Oxford Street, Cambridge

High harmonic generation (HHG) is a unique quantum light source with fundamentally new capabilities – producing fully spatially and temporally coherent beams with linear or circular polarization throughout the extreme ultraviolet (EUV) and soft X-ray region, all on a tabletop. This talk will introduce and review recent developments in HHG sources, as well as exciting advances in spectroscopy of materials. A host of applications in nanoscience and nanotechnology have now been demonstrated, including quantifying how nanoscale energy flow differs from bulk, measuring how fast a material can change its electronic or magnetic state, probing how spin currents can control and enhance magnetization in ultra thin films, and visualizing the dynamic band structure of material and electron-electron interactions on sub-femtosecond timescales. In recent work we measured the shortest lifetime of any state to date, at 212±30 attoseconds, corresponding to an excited state in the band structure of a material. More recently, In particular, a new technique called attosecond-ARPES (angle resolved photoemission) harnesses HHG pulse trains to measure the fastest electron dynamics intrinsic to materials, making it possible to distinguish sub-femtosecond electron scattering and screening for the first time.

Science 353, 62 (2016); Nature Photonics, in press (2017); PNAS 112, 4846–4851 (2015); Physical Review Letters 110, 197201 (2013); Science 348, 530 (2015).

"Coherent imaging using coherent X-ray beams"

Thursday, April 12, 2018 @ 2:00pm
Jefferson 250, 17 Oxford Street, Cambridge

Nanoscale imaging is critical for discovery and innovation in science and technology, accelerating advances in materials, bio, nano and energy sciences, as well as nanoelectronics, data storage and medicine. Due to exciting advances in sources, detectors, algorithms and methodologies, electron, X ray and visible microscopies are all undergoing revolutionary advances. For example, ever since the invention of the laser over 50 years ago, scientists have been striving to create an x-ray version of the laser. Over the past 10 years, advances in extreme nonlinear optics now make it possible to efficiently upshift tabletop femtosecond lasers into the ultraviolet (EUV) and soft X-ray regions of the spectrum, to wavelengths as short as 8 Å. This unique high harmonic light source is making it possible to build the first perfect X-ray microscopes, that can image buried interfaces. This talk will also describe the new STROBE NSF Center on Real-Time Functional Imaging.

Dr. Margaret Murnane is Director of the US National Science Foundation STROBE Science and Technology Center on functional nanoimaging, a Fellow at JILA and a member of the Department of Physics and Electrical and Computer Engineering at the University of Colorado. She received her B.S and M.S. degrees from University College Cork, Ireland, and her Ph.D. degree in physics from the University of California at Berkeley in 1989. She runs a joint research group and a small laser company with her husband, Prof. Henry Kapteyn. Margaret's research interests have been in ultrafast laser and x-ray science. She is a Fellow of the American Physical Society, the Optical Society of America and the AAAS. Her honors include the Maria Goeppert-Mayer Award of the American Physical Society, a John D. and Catherine T. MacArthur Fellowship, and election to the National Academy of Sciences, the American Academy of Arts and Sciences, the American Phiosophical Society, and the Royal Irish Academy. She has done extensive service, including as the Chair of the President’s Committee for the (US) National Medals of Science. She is the 2017 recipient of the Ives Medal/ Quinn Prize of the Optical Society of America– the OSA’s highest honor.