Strain effects in phosphorous bound exciton transitions in silicon

TL;DR

This study investigates how strain from microfabricated electrodes affects phosphorous donor bound exciton transitions in silicon, crucial for scalable quantum spin readout, and demonstrates potential for integration with silicon photonics.

Contribution

It provides a detailed analysis of strain effects on exciton transitions in silicon using hybrid electro-optical methods, enabling scalable quantum information applications.

Findings

Significant zero-field splitting observed due to strain

Strain causes mixing of hole states modeled by Pikus-Bir Hamiltonian

Hybrid spin readout in silicon-on-insulator platforms is feasible

Abstract

Donor spin states in silicon are a promising candidate for quantum information processing. One possible donor spin readout mechanism is the bound exciton transition that can be excited optically and creates an electrical signal when it decays. This transition has been extensively studied in bulk, but in order to scale towards localized spin readout, microfabricated structures are needed for detection. As these electrodes will inevitably cause strain in the silicon lattice, it will be crucial to understand how strain affects the exciton transitions. Here we study the phosphorous donor bound exciton transitions in silicon using hybrid electro-optical readout with microfabricated electrodes. We observe a significant zero-field splitting as well mixing of the hole states due to strain. We can model these effects assuming the known asymmetry of the hole g-factors and the Pikus-Bir Hamiltonian describing the strain. In addition, we describe the temperature, laser power and light polarization dependence of the transitions. Importantly, the hole-mixing should not prevent donor electron spin readout and using our measured parameters and numerical simulations we anticipate that hybrid spin readout in a silicon-on-insulator platform should be possible, allowing integration to silicon photonics platforms.