Electron spin as a spectrometer of nuclear spin noise and other fluctuations

TL;DR

This paper explores how electron spin coherence measurements can serve as a spectrometer for nuclear spin noise and other fluctuations, linking noise spectral functions to spin decay in semiconductors.

Contribution

It provides a theoretical framework connecting noise spectra to spin coherence decay and includes detailed calculations and experimental comparisons.

Findings

Noise spectral functions can be directly related to electron spin coherence decay.

Microscopic calculations of nuclear spin noise spectra match experimental data.

Hyperfine interactions significantly influence spin decoherence in semiconductors.

Abstract

This chapter describes the relationship between low frequency noise and coherence decay of localized spins in semiconductors. Section 2 establishes a direct relationship between an arbitrary noise spectral function and spin coherence as measured by a number of pulse spin resonance sequences. Section 3 describes the electron-nuclear spin Hamiltonian, including isotropic and anisotropic hyperfine interactions, inter-nuclear dipolar interactions, and the effective Hamiltonian for nuclear-nuclear coupling mediated by the electron spin hyperfine interaction. Section 4 describes a microscopic calculation of the nuclear spin noise spectrum arising due to nuclear spin dipolar flip-flops with quasiparticle broadening included. Section 5 compares our explicit numerical results to electron spin echo decay experiments for phosphorus doped silicon in natural and nuclear spin enriched samples.