Limit-Cycles and Chaos in the Current Through a Quantum Dot

TL;DR

This paper explores complex non-linear behaviors like limit-cycles and chaos in the current through a quantum dot influenced by ferromagnetic leads and anisotropic exchange interactions, revealing how magnetic field and coupling affect these phenomena.

Contribution

It introduces a detailed analysis of non-linear magneto-transport in quantum dots with ferromagnetic leads, highlighting the emergence of limit-cycles and chaos due to anisotropic exchange coupling.

Findings

Identification of regimes with self-sustained oscillations in current

Mapping of chaos dependence on magnetic field and tunnel coupling

Demonstration of limit-cycle behavior in quantum dot transport

Abstract

We investigate non-linear magneto-transport through a single level quantum dot coupled to ferromagnetic leads, where the electron spin is coupled to a large, external (pseudo)spin via an anisotropic exchange interaction. We find regimes where the average current through the dot displays self-sustained oscillations that reflect the limit-cycles and chaos and map the dependence of this behaviour on magnetic field strength and the tunnel coupling to the external leads.