SIMES Seminar Series

Date(s) - Jan 18 2013
11:00 AM - 12:30 PM

Shasta Room, Bldg. 40, Room 361


David Reis: “Time-resolved x-ray scattering: What’s new?”

In this talk, I will try to answer this  question by focusing on complementary new information about the excitations in solids that we can obtain by working in the time as opposed to frequency domain.  As an example, I will discuss recent experiments on LCLS [Trigo et al.] where we measured coherent oscillations in the density-density correlation function due to the sudden excitation of correlated pairs of high momentum transverse acoustic phonons in germanium.  The measurements are notable in their spectral resolution given that we use broad-band non resonant x-ray pulses, highly parallel detection and do not resolve the energy of the scattered photons.  I will discuss the interpretation of the measurement in terms of the generic generation and detection mechanism and discuss possible applications to advanced materials.

M. Trigo, M. Fuchs, J. Chen, M. P. Jiang, M. E. Kozina, et al., Direct measurement of time-dependent density-density correlations in a solid through the acoustic analog of the dynamical Casimir effect, submitted to Nature, 2013.