Cavity Control over Heavy-Hole Spin Qubits in Inversion-Symmetric Crystals

TL;DR

This paper explores cavity-mediated control and coupling of heavy-hole spin qubits in inversion-symmetric crystals, specifically Germanium, achieving strong coupling regimes with MHz Rabi frequencies.

Contribution

It introduces a cavity-based manipulation scheme for heavy-hole spins in inversion-symmetric materials using cubic Rashba SOI, advancing quantum dot qubit control methods.

Findings

Derived an effective cavity-mediated spin coupling for Germanium quantum dots.

Proposed parameters enabling Rabi frequencies in the MHz range.

Achieved conditions for strong cavity quantum electrodynamics coupling.

Abstract

The pseudospin of heavy-holes (HHs) confined in a semiconductor quantum dot (QD) represents a promising candidate for a fast and robust qubit. While hole spin manipulation by a classical electric field utilizing the Dresselhaus spin-orbit interaction (SOI) has been demonstrated, our work explores cavity-based qubit manipulation and coupling schemes for inversion-symmetric crystals forming a planar HH QD. Choosing the exemplary material Germanium (Ge), we derive an effective cavity-mediated ground state spin coupling that harnesses the cubic Rashba SOI. In addition, we propose an optimal set of parameters which allows for Rabi frequencies in the MHz range, thus entering the strong coupling regime of cavity quantum electrodynamics.