Nuclear spin readout in a cavity-coupled hybrid quantum dot-donor system

TL;DR

This paper proposes a method to read out nuclear spins in a silicon quantum dot-donor system using microwave transmission, enabling potential quantum information applications with long coherence times.

Contribution

It introduces a theoretical approach for nuclear spin readout via microwave cavity transmission in a hybrid quantum dot-donor system, highlighting optimal conditions for experimental realization.

Findings

Nuclear spin readout is feasible with current technology.

Optimal readout points with strong signal contrast are identified.

Potential for coherent exchange between nuclear spins and cavity photons is demonstrated.

Abstract

Nuclear spins show long coherence times and are well isolated from the environment, which are properties making them promising for quantum information applications. Here, we present a method for nuclear spin readout by probing the transmission of a microwave resonator. We consider a single electron in a silicon quantum dot-donor device interacting with a microwave resonator via the electric dipole coupling and subjected to a homogeneous magnetic field and a transverse magnetic field gradient. In our scenario, the electron spin interacts with a $^{31}\mathrm{P}$ defect nuclear spin via the hyperfine interaction. We theoretically investigate the influence of the P nuclear spin state on the microwave transmission through the cavity and show that nuclear spin readout is feasible with current state-of-the-art devices. Moreover, we identify optimal readout points with strong signal contrast to facilitate the experimental implementation of nuclear spin readout. Furthermore, we investigate the potential for achieving coherent excitation exchange between a nuclear spin qubit and cavity photons.