Spin-photon coupling for atomic qubit devices in silicon

TL;DR

This paper proposes a method to couple microwave photons to silicon-based atomic spin qubits using hyperfine interaction and spin-orbit coupling, enabling scalable quantum processing without external magnetic field gradients.

Contribution

It introduces a novel approach to achieve strong spin-photon coupling in silicon donor systems, avoiding the need for external magnetic field gradients.

Findings

Strong spin-photon coupling is achievable in 1P-1P systems.

The method does not require external magnetic field gradients.

Analysis compares 1P-1P systems with double quantum dots.

Abstract

Electrically addressing spin systems is predicted to be a key component in developing scalable semiconductor-based quantum processing architectures, to enable fast spin qubit manipulation and long-distance entanglement via microwave photons. However, single spins have no electric dipole, and therefore a spin-orbit mechanism must be integrated in the qubit design. Here, we propose to couple microwave photons to atomically precise donor spin qubit devices in silicon using the hyperfine interaction intrinsic to donor systems and an electrically-induced spin-orbit coupling. We characterise a one-electron system bound to a tunnel-coupled donor pair (1P-1P) using the tight-binding method, and then estimate the spin-photon coupling achievable under realistic assumptions. We address the recent experiments on double quantum dots (DQDs) in silicon and indicate the differences between DQD and 1P-1P systems. Our analysis shows that it is possible to achieve strong spin-photon coupling in 1P-1P systems in realistic device conditions without the need for an external magnetic field gradient.