High precision quantum control of single donor spins in silicon

TL;DR

This paper demonstrates highly precise quantum control of single donor spins in silicon by accurately modeling the Stark effect, aligning theory with experiments, and highlighting interface effects crucial for quantum computing.

Contribution

The work provides the most sensitive comparison between theoretical models and experimental data for single donor spin control in silicon, using advanced tight-binding calculations.

Findings

Quadratic Stark coefficient matches experimental results closely.

Linear Stark effect is significant near interfaces.

Quadratic Stark effect dominates far from interfaces.

Abstract

The Stark shift of the hyperfine coupling constant is investigated for a P donor in Si far below the ionization regime in the presence of interfaces using Tight-binding and Band Minima Basis approaches and compared to the recent precision measurements. The TB electronic structure calculations included over 3 million atoms. In contrast to previous effective mass based results, the quadratic Stark coefficient obtained from both theories agrees closely with the experiments. This work represents the most sensitive and precise comparison between theory and experiment for single donor spin control. It is also shown that there is a significant linear Stark effect for an impurity near the interface, whereas, far from the interface, the quadratic Stark effect dominates. Such precise control of single donor spin states is required particularly in quantum computing applications of single donor electronics, which forms the driving motivation of this work.