Faraday Rotation with Single Nuclear Spin Qubit in a High-Finesse Optical Cavity

TL;DR

This paper demonstrates significant Faraday rotation caused by a single nuclear spin in a high-finesse optical cavity, enabling spin measurement and control via photon interactions, advancing quantum information processing techniques.

Contribution

It presents the first observation of large Faraday rotation with a single nuclear spin in an optical cavity and shows spin measurement through photon projection.

Findings

Observed >10° Faraday rotation with a single 171Yb nuclear spin.

Demonstrated spin projection and weak measurement via transmitted photon.

Established a platform for quantum spin-photon interactions.

Abstract

When an off-resonant light field is coupled with atomic spins, its polarization can rotate depending on the direction of the spins via a Faraday rotation which has been used for monitoring and controlling the atomic spins. We observed Faraday rotation by an angle of more than 10 degrees for a single 1/2 nuclear spin of 171Yb atom in a high-finesse optical cavity. By employing the coupling between the single nuclear spin and a photon, we have also demonstrated that the spin can be projected or weakly measured through the projection of the transmitted single ancillary photon.