Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 28: FS: Time-Resolved Spectroscopy in Correlated Electron Systems:
Experiment and Theory

TT 28.2: Hauptvortrag

Donnerstag, 25. März 2010, 10:00–10:30, H18

Many Body Theory for Time-Resolved Pump/Probe Photoemission and its Solution via Nonequilibrium Dynamical Mean-Field Theory — •James Freericks — Georgetown University, Washington, DC, USA

In this talk, I will present the exact many-body formalism for time-resolved pump/probe photoemission spectroscopy (PES). By using the sudden approximation and neglecting the energy and momentum dependence of matrix elements, one can reduce the PES response to a relative time Fourier transform of the (nonequilibrium) lesser Green’s function in the presence of the pump and modulated by the probe envelope. We will apply this theory to a system that cannot be described by a quasiequilibrium approach with a time-dependent effective temperature: namely, the response of the system to a large dc electric field which generates damped Bloch oscillations in the system as it evolves to a nonequilibrium steady state. We will describe the interplay between the probe width and the ability to see temporal oscillations or sharp features in the spectra.

Recent references include: J. K. Freericks, H. R. Krishnamurthy and Th. Pruschke, Phys. Rev. Lett. 102, 136401 (2009); J. K. Freericks, H. R. Krishnamurthy, Yizhi Ge, A. Y. Liu, and Th. Pruschke, phys. stat. sol. b 246, 948 (2009); and B. Moritz, T. P. Devereaux, and J. K. Freericks, arXiv:0908.1807.