Transient Dynamics of a Quantum-Dot in the Mixed Valence Regime

TL;DR

This paper studies the transient and steady state transport dynamics of a strongly correlated quantum dot in the mixed valence regime using the HEOM approach, revealing linear and nonlinear response behaviors influenced by temperature, bias, and Kondo physics.

Contribution

It introduces a detailed analysis of quantum dot dynamics in the mixed valence regime using hierarchical equations of motion, highlighting the effects of bias, temperature, and interactions on transport properties.

Findings

Linear response for weak bias voltage

Nonlinear behavior at larger bias due to quantum dot occupancy transition

Temperature and interaction effects influence steady state current and Kondo physics

Abstract

We investigate the dynamics of a strongly correlated quantum dot system in the mixed valence regime based on the hierarchical equations of motion (HEOM) approach. The transient and steady state transport properties after a quantum quench from equilibration by rapidly applying a bias voltage in a range of temperature below and above the Kondo temperature are described. We find that the time-dependent current exhibits a linear response behavior for weak bias voltage and outside of the linear response regime for larger bias voltage due to the transition of the voltage dependent quantum dot occupancies. The influence of the temperature, finite strongly correlated electron-electron interaction and energy level of the quantum dot on the nonlinear behavior and steady state values of current indicating the Kondo physics are explored in detail.