Terahertz Emission From Diamond Nitrogen-Vacancy Centers

TL;DR

This paper demonstrates a novel method for generating tunable terahertz radiation using nitrogen-vacancy centers in diamond, achieved through Zeeman splitting and phase-sensitive detection, with potential for advanced THz sources.

Contribution

It introduces a new approach to produce tunable THz radiation from NV centers in diamond via magnetic field manipulation and ESR detection.

Findings

Achieved population inversion in NV centers using Zeeman splitting.

Detected tunable THz radiation with phase-sensitive setup.

Measured spin-lattice relaxation times up to 15 T.

Abstract

Coherent light sources emitting in the terahertz range are highly sought after for fundamental research and applications. THz lasers rely on achieving population inversion. We demonstrate the generation of THz radiation using nitrogen-vacancy (NV) centers in a diamond single crystal. Population inversion is achieved through the Zeeman splitting of the $S=1$ state in $15\ \text{T}$, resulting in a splitting of $0.42\ \text{THz}$, where the middle $S_z=0$ sublevel is selectively pumped by visible light. To detect the THz radiation, we utilize a phase-sensitive THz setup, optimized for electron spin resonance measurements (ESR). We determine the spin-lattice relaxation time up to $15\ \text{T}$ using the light-induced ESR measurement, which shows the dominance of phonon-mediated relaxation and the high efficacy of the population inversion. The THz radiation is tunable by the magnetic field, thus these findings may lead to the next generation of tunable coherent THz sources.