Resonant Cooling of Nuclear Spins in Quantum Dots

TL;DR

This paper introduces a method to significantly reduce nuclear spin fluctuations in quantum dots by leveraging a feedback mechanism similar to Doppler cooling, enhancing electron spin measurement stability.

Contribution

It presents a novel approach using the spin-blockade regime to suppress nuclear spin noise in quantum dots, achieving over tenfold reduction in fluctuations.

Findings

Over 10-fold reduction in nuclear spin fluctuations possible

Feedback mechanism stabilizes electron spin levels

Potential improvements in quantum dot spin coherence

Abstract

We propose to use the spin-blockade regime in double quantum dots to reduce nuclear spin polarization fluctuations in analogy with optical Doppler cooling. The Overhauser shift brings electron levels in and out of resonance, creating feedback to suppress fluctuations. Coupling to the disordered nuclear spin background is a major source of noise and dephasing in electron spin measurements in such systems. Estimates indicate that a better than 10-fold reduction of fluctuations is possible.