Revealing the internal spin dynamics in a double quantum dot by periodic voltage modulation

TL;DR

This paper introduces a method to analyze internal spin dynamics in double quantum dots through periodic voltage modulation and current measurement, revealing coherent spin oscillations and their dependence on modulation frequency and exchange coupling.

Contribution

The paper presents a novel approach to probe internal spin dynamics in quantum dots by using periodic voltage modulation and analyzing the resulting current behavior.

Findings

Current depends on modulation frequency and exchange coupling.

Oscillatory behavior of current reveals coherent spin oscillations.

Method can distinguish different internal spin states.

Abstract

The paper proposes the method to analyze the internal dynamics of nanoscopic systems by periodic modulation of the electrochemical potentials of the attached leads and measuring the time-averaged current. The idea is presented using the example of the a double quantum dot coupled to one nonmagnetic and one spin-polarized lead. The current flowing through the molecule is shown to depend on both the frequency of the modulation and the exchange coupling between the electrons occupying the molecule. In particular, one can observe a pronounced oscillatory behavior of the current-frequency dependence, which reveals the coherent oscillations between the spin states of the system.