Kondo memory in driven strongly-correlated quantum dots

TL;DR

This paper studies how Kondo resonance causes significant memory effects in the real-time current response of driven strongly-correlated quantum dots, revealing hysteresis, overtones, and temperature-dependent transitions.

Contribution

It demonstrates the presence of Kondo-induced memory effects in quantum dots under sinusoidal driving using hierarchical equations of motion, highlighting their quantum-coherent origin.

Findings

Memory effects manifest as hysteresis and self-crossing in current-voltage curves.

Memory effects are suppressed and classical behavior emerges at higher temperatures.

Odd overtones are excited due to quantum coherence and electron correlations.

Abstract

We investigate the real-time current response of strongly-correlated quantum dot systems under sinusoidal driving voltages. By means of an accurate hierarchical equations of motion approach, we demonstrate the presence of prominent memory effects induced by the Kondo resonance on the real-time current response. These memory effects appear as distinctive hysteresis line shapes and self-crossing features in the dynamic current-voltage characteristics, with concomitant excitation of odd-number overtones. They emerge as a cooperative effect of quantum coherence - due to inductive behavior - and electron correlations - due to the Kondo resonance. We also show the suppression of memory effects and the transition to classical behavior as a function of temperature. All these phenomena can be observed in experiments and may lead to novel quantum memory applications.