Quadrupolar Effects on Nuclear Spins of Neutral Arsenic Donors in Silicon

TL;DR

This study investigates quadrupolar effects on arsenic nuclear spins in strained silicon, revealing significant quadrupole interactions influenced by the electron wavefunction and strain, with implications for quantum information applications.

Contribution

It provides the first measurement of quadrupole interactions of neutral arsenic donors in strained silicon and links these effects to changes in the electron wavefunction.

Findings

Significant quadrupole interactions (~10 kHz) observed in neutral arsenic donors.

Comparison shows the electron influences electric field gradients at the nucleus.

Strain-induced changes affect hyperfine coupling and quadrupole shifts.

Abstract

We present electrically detected electron nuclear double resonance measurements of the nuclear spins of ionized and neutral arsenic donors in strained silicon. In addition to a reduction of the hyperfine coupling, we find significant quadrupole interactions of the nuclear spin of the neutral donors of the order of 10 kHz. By comparing these to the quadrupole shifts due to crystal fields measured for the ionized donors, we identify the effect of the additional electron on the electric field gradient at the nucleus. This extra component is expected to be caused by the coupling to electric field gradients created due to changes in the electron wavefunction under strain.