Impact ionisation processes in the periodic steady state of a driven Hubbard chain

Recently, Mott-insulating heterostructures have been proposed as
candidates for highly efficient solar cells [1]. Here, photoexcited
doublons and holes act as charge carriers which can proliferate due to impact ionisation processes [2].
Previous works have investigated the doublon dynamics in such systems within
time-dependent Dynamical Mean-Field Theory (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 quantum systems. Specifically, we implement an
algorithm to deal with periodic steady states of strongly correlated
systems, making use of the nonequilibrium Floquet Green's function
formalism within the DMFT approximation.
Our model consists of a correlated layer subject to a periodic driving
via a homogeneous electric field and coupled to leads with different
chemical potentials.

We present results obtained with a Floquet DMFT implementation using the
Auxiliary Master Equation Approach (AMEA) [4] as an impurity solver.
AMEA is based upon mapping the system to an open quantum system
described by a Lindblad Master Equation. This allows the impurity to be
affected by short-ranged non-Markovian dynamics.
For comparison, we also carry out calculations on the same model within iterated perturbation
theory [5]

[1] E. Manousakis, Phys. Rev. B, 82, 125109, (2010); E.Assman et al., Phys. Rev. Lett. 110, 078701 (2013)
[2] J.Coulter et al., Phys. Rev. B, 90,165142 (2014)
[3] M.Eckstein and P. Werner, Phys. Rev. Lett., 113, 076405 (2014); P. Werner et al., Phys. Rev. B 90, 235102 (2014)
[4] E. Arrigoni et al., Phys. Rrev. Lett., 110, 086403 (2013); I. Titvinidze et al., Phys. Rev. B, 92, 245125 (2015)
[5] A. Joura et al., Phys Rrev. B, 91, 245153 (2015)