Spin Lifetimes in Quantum Dots from Noise Measurements

TL;DR

This paper introduces a method to determine spin lifetimes in quantum dots by analyzing electrical transport noise spectra under microwave irradiation, revealing the ratio of spin coherence times from current measurements.

Contribution

It provides a novel approach to extract spin relaxation and decoherence times from noise measurements in quantum dots under specific conditions.

Findings

The ratio T₁/T₂ can be inferred from current measurements.

A dip in the noise power spectrum occurs at the Rabi frequency.

The dip's line width relates to 1/T₁ + 1/T₂.

Abstract

We present a method of obtaining information about spin lifetimes in quantum dots from measurements of electrical transport. The dot is under resonant microwave irradiation and at temperatures comparable to or larger than the Zeeman energy. We find that the ratio of the spin coherence times T_{1}/T_{2} can be deduced from a measurement of current through the quantum dot as a function the applied magnetic field. We calculate the noise power spectrum of the dot current and show that a dip occurs at the Rabi frequency with a line width given by 1/T_{1}+1/T_{2}.