Multiple-quantum transitions and charge-induced decoherence of donor nuclear spins in silicon

TL;DR

This paper investigates how charge-induced electric field gradients affect the coherence of arsenic donor nuclear spins in silicon, revealing quadrupolar effects and their impact on quantum coherence times.

Contribution

It introduces a phase-cycling technique to measure coherence times of multi-quantum superpositions in nuclear spins under electrical perturbations.

Findings

Quadrupolar effects influence nuclear spin coherence times.

Electrical field gradients cause decoherence linked to surrounding nuclear spins.

Coherence times scale as expected for field-like decoherence mechanisms.

Abstract

We study single- and multi-quantum transitions of the nuclear spins of ionized arsenic donors in silicon and find quadrupolar effects on the coherence times, which we link to fluctuating electrical field gradients present after the application of light and bias voltage pulses. To determine the coherence times of superpositions of all orders in the 4-dimensional Hilbert space, we use a phase-cycling technique and find that, when electrical effects were allowed to decay, these times scale as expected for a field-like decoherence mechanism such as the interaction with surrounding $^{29}$Si nuclear spins.