MSE Areas: Nanoscale thermal transport, nanoscale acoustic metrology, ultrafast spin dynamics, ultrafast x-ray photoemission of surfaces and phase change materials
The thrust of research in our group is in ultrafast x-ray science and applications. X-ray wavelengths correspond to the scale relevant to nanotechnology (~1-100mm). Ultrafast few-femtosecond x-ray pulses can capture all dynamics relevant to function [1-3]. Coherent x-ray beams enable imaging at the wavelength limit. To make rapid progress in nano, a wide variety of techniques are needed to see, manipulate, and follow function at the nano-femto limits. Ultrafast x-rays can capture the fastest coupled motions of charge/spin/phonon/photons in materials, probe thick objects, capture catalytic function in molecular and surface systems, and probe nano-mechanical properties – all of which are complimentary to other existing nano probes such as atomic force microscopes. Thus, ultrafast coherent x-ray beams promise to become indispensable tools in the quest to develop better nanoscale materials systems.
Mark Siemens, Qing Li, Ronggui Yang, Keith Nelson, Erik Anderson, Margaret Murnane and Henry Kapteyn, “Measurement of quasi-ballistic heat transport across nanoscale interfaces using ultrafast coherent soft x-ray beams”, Nature Materials 9, 26 (2010).
M. Seaberg, D. Adams, E. Townsend, D. Raymondson, W. F. Schlotter, Y. Liu, C. Menoni, H. C. Kapteyn, and M. M. Murnane, “Ultrahigh 22 nm Resolution Coherent Diffractive Imaging using a Desktop 13 nm High Harmonic Source,” Optics Express 19, 22470 (2011).
D. Rudolf, C. La-O-Vorakiat, M. Battiato, R. Adam, J.M. Shaw, E. Turgut, P. Maldonado, S. Mathias, P. Grychtol, H.T. Nembach, T.J. Silva, M. Aeschlimann, H.C. Kapteyn, M.M. Murnane, C.M. Schneider, P.M. Oppeneer, “Ultrafast magnetization enhancement in metallic multilayers driven by superdiffusive spin current“, to be published in Nature Communications (2012).