Gauge invariance in the theoretical description of time-resolved angle-resolved pump/probe photoemission spectroscopy

Freericks, JK and Krishnamurthy, HR and Sentef, MA and Devereaux, TP (2015) Gauge invariance in the theoretical description of time-resolved angle-resolved pump/probe photoemission spectroscopy. In: PHYSICA SCRIPTA, T165 .

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Abstract

Nonequilibrium calculations in the presence of an electric field are usually performed in a gauge, and need to be transformed to reveal the gauge-invariant observables. In this work, we discuss the issue of gauge invariance in the context of time-resolved angle-resolved pump/probe photoemission. If the probe is applied while the pump is still on, one must ensure that the calculations of the observed photocurrent are gauge invariant. We also discuss the requirement of the photoemission signal to be positive and the relationship of this constraint to gauge invariance. We end by discussing some technical details related to the perturbative derivation of the photoemission spectra, which involve processes where the pump pulse photoemits electrons due to nonequilibrium effects.

Item Type:	Journal Article
Publication:	PHYSICA SCRIPTA
Publisher:	IOP PUBLISHING LTD
Additional Information:	Copy right for this article belongs to the IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Keywords:	pump/probe time-resolved photoemission; gauge invariance; nonequilibrium many-body physics
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 Jan 2016 07:45
Last Modified:	28 Jan 2016 07:45
URI:	http://eprints.iisc.ac.in/id/eprint/53185

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