Nuclear spin cooling using Overhauser field selective coherent population trapping

TL;DR

This paper demonstrates a method to suppress electronic spin dephasing in solid-state emitters by using optical interference to control nuclear spin states, enhancing coherence times.

Contribution

It introduces a novel optical interference technique to prepare nuclear spins in specific states, reducing electron spin dephasing in solid-state systems.

Findings

Nuclear spin states can be controlled via optical interference effects.

The method suppresses electron spin dephasing by narrowing nuclear spin distributions.

The approach enables measurement of nuclear magnetic fields through resonance fluorescence.

Abstract

Hyperfine interactions with a nuclear spin environment fundamentally limit the coherence properties of confined electron spins in the solid-state. Here, we show that a quantum interference effect in optical absorption from two electronic spin states of a solid-state emitter can be used to prepare the surrounding environment of nuclear spins in well-defined states, thereby suppressing electronic spin dephasing. The evolution of the coupled electron-nuclei system into a coherent population trapping state by optical excitation induced nuclear spin diffusion can be described in terms of Levy flights, in close analogy with sub-recoil laser cooling of atoms. The large difference in electronic and nuclear time scales simultaneously allow for a measurement of the magnetic field produced by nuclear spins, making it possible to turn the lasers that cause the anomalous spin diffusion process off when the strength of the resonance fluorescence reveals that the nuclear spins are in the desired narrow state.