Disentangling the exchange coupling of entangled donors in the Si quantum computer architecture

TL;DR

This paper presents a theoretical study of micro-Raman scattering in silicon, showing its potential to measure interdonor exchange coupling crucial for silicon-based quantum computing.

Contribution

The authors develop a theory linking Raman spectra to donor exchange interactions and spatial arrangements in silicon quantum computers.

Findings

Raman spectra depend on donor exchange splitting and positions.

Temperature affects Raman peak intensity correlated with exchange coupling.

Micro-Raman scattering can measure interqubit coupling in silicon.

Abstract

We develop a theory for micro-Raman scattering by single and coupled two-donor states in silicon. We find the Raman spectra to have significant dependence on the donor exchange splitting and the relative spatial positions of the two donor sites. In particular, we establish a strong correlation between the temperature dependence of the Raman peak intensity and the interdonor exchange coupling. Micro-Raman scattering can therefore potentially become a powerful tool to measure interqubit coupling in the development of a Si quantum computer architecture.