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arXiv · 0809.2347

Theoretical description of time-resolved pump/probe photoemission in TaS\_2: a single-band DFT+DMFT(NRG) study within the quasiequilibrium approximation

J. K. Freericks·H. R. Krishnamurthy·Yizhi Ge·A. Y. Liu·Th. Pruschke
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Abstract

In this work, we theoretically examine recent pump/probe photoemission experiments on the strongly correlated charge-density-wave insulator TaS\_2. We describe the general nonequilibrium many-body formulation of time-resolved photoemission in the sudden approximation, and then solve the problem using dynamical mean-field theory with the numerical renormalization group and a bare density of states calculated from density functional theory including the charge-density-wave distortion of the ion cores and spin-orbit coupling We find a number of interesting results: (i) the bare band structure actually has more dispersion in the perpendicular direction than in the two-dimensional planes; (ii) the DMFT approach can produce upper and lower Hubbard bands that resemble those in the experiment, but the upper bands will overlap in energy with other higher energy bands; (iii) the effect of the finite width of the probe pulse is minimal on the shape of the photoemission spectra; and (iv) the quasiequilibrium approximation does not fully describe the behavior in this system.

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J. K. Freericks, H. R. Krishnamurthy, Yizhi Ge, A. Y. Liu, Th. Pruschke. 2008-09-13. Theoretical description of time-resolved pump/probe photoemission in TaS\_2: a single-band DFT+DMFT(NRG) study within the quasiequilibrium approximation. https://doi.org/10.1002/pssb.200881555

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