One step model description of photoemission: Correlations, Matrix elements and Temperature effects

Abstract: Various technical developments enlarged the potential of angle-resolved photoemission (ARPES) tremendously during the last one or two decades. In particular improved momentum, energy and spin resolution as well as the use of photon energies from few eV up to several keV makes ARPES a rather unique tool to investigate the electronic properties of solids and surfaces [1,2,3]. These experimental developments needs to be closely followed by corresponding theoretical description beyond simple interpretations like e.g. spectral function or DOS. Here, we present a generalization of the state of the art description of the photoemission process, the so called one-step model that describes excitation, transport to the surface and escape into the vacuum in a coherent way. Within this approach we account for correlation effects by LSDA+DMFT, disorder by means of CPA. In this presentation I will concentrate on the spin polarised surface states as probed by the ARPES such as topological surface states in Bi2Se3 and Bi2Te3 [4] and their manipulation by using pump-probe spin resolved ARPES [5].

[1] A. Gray, etl al. Nat. Mat. 10, 759 (2011), A. Gray et al. Nat. Mat. 11, 957 (2012)
[2] Minar et al., J. El. Spec. Rel. Phen. 190, 159 (2013)
[3] M. Jourdan et al., Nat. Com. 5, 3974 (2014)
[4] Barriga et al. PRL 110, 216801 (2013) and PRX 4, 011046 (2014)
[5] Cacho et al., Phys. Rev. Lett. 114, 097401 (2015)