Universal Scaling of Hyperfine-Induced Electron Spin Echo Decay

TL;DR

This paper investigates how hyperfine interactions cause electron spin decoherence in solid-state systems and demonstrates that spin echo sequences can nearly reverse these effects, revealing a universal scaling law for decoherence depending on system parameters.

Contribution

It introduces a universal scaling law for hyperfine-induced decoherence and shows spin echo sequences can effectively suppress this decoherence in high-field regimes.

Findings

Spin echo sequences can nearly reverse hyperfine-induced nuclear spin dynamics.

Decoherence magnitude scales universally with inhomogeneous line width and magnetic field.

Hyperfine interactions significantly contribute to electron spin phase fluctuations.

Abstract

The decoherence of a localized electron spin in a lattice of nuclear spins is an important problem for potential solid-state implementations of a quantum computer. We demonstrate that even at high fields, virtual electron spin-flip processes due solely to the hyperfine interaction can lead to complex nuclear spin dynamics. These dynamics, in turn, can lead to single electron spin phase fluctuation and decoherence. We show here that remarkably, a spin echo pulse sequence can almost completely reverse these nuclear dynamics except for a small visibility loss, thereby suppressing contribution of the hyperfine interaction to T_2 processes. For small systems, we present numerical evidence which demonstrates a universal scaling of the magnitude of visibility loss that depends only on the inhomogeneous line width of the system and the magnetic field.