Nuclear Tuning and Detuning of the Electron Spin Resonance in a Quantum Dot

TL;DR

This paper investigates how nuclear spins influence electron spin resonance in quantum dots, revealing bistability and nuclear field tuning effects that impact spin coherence and relaxation.

Contribution

It uncovers the dual role of nuclear fields in detuning and tuning electron spin resonance, demonstrating nuclear bistability and its effects on spin dynamics.

Findings

Nuclear fields can detune or tune the resonance depending on frequency mismatch.

Bistability occurs in nuclear spin states, affecting resonance conditions.

Nuclear field fluctuations are suppressed in the tuning state.

Abstract

We study nuclear spin dynamics in a quantum dot close to the conditions of electron spin resonance. We show that at small frequency mismatch the nuclear field detunes the resonance. Remarkably, at larger frequency mismatch its effect is opposite: The nuclear system is bistable, and in one of the stable states the field accurately tunes the electron spin splitting to resonance. In this state the nuclear field fluctuations are strongly suppressed and nuclear spin relaxation is accelerated.