Mapping spin coherence of a single rare-earth ion in a crystal onto a single photon polarization state

TL;DR

This paper demonstrates the optical detection and control of a single Ce3+ ion's spin in YAG crystal at room temperature, enabling direct mapping of its quantum state onto a photon’s polarization, advancing quantum communication interfaces.

Contribution

It introduces a method to map the spin coherence of a single rare-earth ion onto a single photon’s polarization state at room temperature.

Findings

Successful optical detection of a single Ce3+ ion in YAG.

Room-temperature control of the ion's spin state.

Direct mapping of spin state onto photon polarization.

Abstract

We report on optical detection of a single photostable Ce3+ ion in an yttrium aluminium garnet (YAG) crystal and on its magneto-optical properties at room temperature. The quantum state of an electron spin of the emitting level of cerium ion in YAG can be initialized by circularly polarized laser pulse. Furthermore, its quantum state can be read out by observing temporal behaviour of circularly polarized fluorescence of the ion. This implies direct mapping of the spin quantum state of Ce3+ ion onto the polarization state of the emitted photon and represents one-way quantum interface between a single spin and a single photon.