Theory of the Stark Effect for P donors in Si

TL;DR

This paper develops a multi-valley effective mass theory to analyze the Stark effect on phosphorus donors in silicon, providing insights crucial for quantum computing applications.

Contribution

It introduces a perturbative approach to valley-orbit coupling in inhomogeneous environments, improving accuracy at high electric fields and matching experimental binding energies.

Findings

Ground state energy increases with electric field due to spectrum narrowing.

Method becomes more accurate at high fields.

Results are relevant for Kane quantum computer design.

Abstract

We develop a multi-valley effective mass theory for substitutional donors in silicon in an inhomogeneous environment. Valley-orbit coupling is treated perturbatively. We apply the theory to the Stark effect in Si:P. The method becomes more accurate at high fields, and it is designed to give correct experimental binding energies at zero field. Unexpectedly, the ground state energy for the donor electron is found to increase with electric field as a consequence of spectrum narrowing of the 1s manifold. Our results are of particular importance for the Kane quantum computer.