Anisotropic interactions of a single spin and dark-spin spectroscopy in diamond

TL;DR

This paper investigates the anisotropic electron spin interactions of single nitrogen-vacancy centers in diamond using angle-resolved magneto-photoluminescence microscopy, revealing insights into spin dynamics and dark spin coupling at room temperature.

Contribution

It introduces a novel microscopy technique to study anisotropic spin interactions and dark spin coupling in single N-V centers under ambient conditions.

Findings

Observation of negative peaks in photoluminescence linked to spin precession.

Identification of anisotropic relaxation at spin level anti-crossings.

Detection of resonant coupling to dark nitrogen spins.

Abstract

The nitrogen-vacancy (N-V) center in diamond is a promising atomic-scale system for solid-state quantum information processing. Its spin-dependent photoluminescence has enabled sensitive measurements on single N-V centers, such as: electron spin resonance, Rabi oscillations, single-shot spin readout and two-qubit operations with a nearby 13C nuclear spin. Furthermore, room temperature spin coherence times as long as 58 microseconds have been reported for N-V center ensembles. Here, we have developed an angle-resolved magneto-photoluminescence microscopy apparatus to investigate the anisotropic electron spin interactions of single N-V centers at room temperature. We observe negative peaks in the photoluminescence as a function of both magnetic field magnitude and angle that are explained by coherent spin precession and anisotropic relaxation at spin level anti-crossings. In addition, precise field alignment unmasks the resonant coupling to neighboring dark nitrogen spins that are not otherwise detected by photoluminescence. The latter results demonstrate a means of investigating small numbers of dark spins via a single bright spin under ambient conditions.