Thermoelectric properties of a strongly correlated layer

Abstract

In this paper we investigate the effect of strong electronic interactions on the thermoelectric properties of a simple generic system, consisting of a single correlated layer sandwiched between two metallic leads. Results will be given for the linear response regime as well as beyond, for which a full nonequilibrium many-body calculation is performed, based on nonequilibrium dynamical mean-field theory (DMFT). As impurity solver we use the auxiliary master equation approach, which addresses the impurity problem within a finite auxiliary system consisting of a correlated impurity, a small number of uncorrelated bath sites and Markovian environments. For the linear response regime, results will be presented for the Seebeck coefficient, the electrical conductance and the electronic contribution to the thermal conductance. Beyond linear response, i.e. for finite differences in the temperatures and/or the bias voltages in the leads, we study the dependence of the current on various model parameters, such as gate voltage and Hubbard interaction of the central layer. We will give a detailed parameter study as far as the thermoelectric efficiency is concerned. We find that strong correlations can indeed increase the thermopower of the device. In addition, some general theoretical requirements for an efficient thermoelectric device will be given.

Nonequilibrium Kondo effect in a magnetic field: auxiliary master equation approach

“…In summary, it is convenient to use AMEA, whenever very long time scales are needed, or when information over the full energy range is required, as it is the case in the determination of spectral functions. For example, AMEA is an interesting tool for DMFT in nonequilibrium, where spectral functions are needed explicitly [26,[55][56][57][58][59]. On the other hand, the NRG-tDMRG approach is more flexible with respect to the parameter regime, as it uses an explicit renormalization of the impurity.…”

“…For example, AMEA is an interesting tool for DMFT in nonequilibrium, where spectral functions are needed explicitly. 26,[55][56][57][58][59] On the other hand, the NRG-tDMRG approach is more flexible with respect to the parameter regime, as it uses an explicit renormalization of the impurity. In particular, it has proven to be able to describe very strong interactions such as U/Γ = 12 and zero temperature T = 0, see Ref.…”

Density-wave steady-state phase of dissipative ultracold fermions with nearest-neighbor interactions

“…One possible mechanism to explain the proportionality for small ν 2 is the presence of heat exchange between the lattice and the baths, as we expect the heat current in lattice systems to be proportional to ν 2 [88]. In this regime the critical value of the dephasing would then be determined by the rate at which the heat generated by the dephasing is taken out of the system.…”

Universal Majorana thermoelectric noise

“…An external bias voltage is applied to these contacts which may also have different temperatures. Here one may easily tune the system's parameters making the electric current induced by the bias voltage and the electric current excited by the temperature difference interfere with one another leading to a highly nontrivial thermoelectric transport [41,42]. When a nanoscopic setup is designed to host Majorana degrees of freedom, the system's thermoelectric response undergoes essential changes which might be used to identify Majorana fermions in, e.g., normal metal-quantum dot-Majorana bound states junction [43], Majorana-sidecoupled quantum dots [44,45], Majorana bound states system coupled to two normal leads [46].…”