Dresden 2017 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 62: Correlated Electrons: Nonequilibrium Quantum Many-Body Systems 1
TT 62.5: Vortrag
Donnerstag, 23. März 2017, 10:30–10:45, HSZ 304
Towards Mott-Insulator based Photovoltaic devices — •Max Sorantin1, Antonius Dorda1, Wolfgang von der Linden1, Karsten Held2, and Enrico Arrigoni1 — 1Institute for theoretical physics, TU Graz, Austria — 2Institute for solid state physics, TU Vienna, Austria
Recently, Mott-insulating heterostructures have been proposed as candidates for highly efficient solar cells [1] owing to impact ionisation processes [2]. Previous works have investigated the doublon dynamics in such systems within time-dependent DMFT by looking at the time evolution after a photoexcitation [3]. In the present work we focus on the (quasi-) steady state of periodically driven correlated lattice systems within Floquet DMFT. We employ the Auxiliary Master Equation Approach (AMEA) [4] to solve the time averaged impurity problem and assess the validity of this approximation by comparison with Iterated Perturbation Theory (IPT) [5]. Our model consists of a correlated layer, subject to a periodic driving via a homogeneous electric field, coupled to leads with an applied bias voltage. Furthermore, we generalize the system to a multilayer structure where the additional layers are used to model an electric field gradient. Investigating the results for the double accupancy, current and Spectralfunction in dependence of the external driving frequency suggests that impact ionization plays a domniant role in the steady state dynamics.
[1] E. Assman et al., PRL 110 (2013)
[2] J. Coulter et al., PRB 90 (2014)
[3] M. Eckstein et al., PRL 113 (2014);
P. Werner et al., PRB 90 (2014)
[4] E. Arrigoni et al., PRL 110 (2013)
[5] A. Joura et al., PRB 91 (2015)