Energy level structure of diamond silicon vacancy centers in an off-axis magnetic field

TL;DR

This paper presents an experimental method to characterize the energy level structure of individual silicon vacancy centers in diamond under magnetic fields, incorporating strain, Jahn-Teller effects, and magnetic interactions.

Contribution

It introduces a novel approach combining theoretical modeling and experimental measurements to extract key parameters of SiV centers' energy levels, including strain and Jahn-Teller effects.

Findings

Derived coupling rates from spectral measurements.

Verified the theoretical model with magnetic field dependence studies.

Revealed unequal orbital magnetic coupling in SiV states.

Abstract

We report the development of an experimental approach that can characterize the energy level structure of an individual silicon vacancy (SiV) center in a magnetic field and extract the key parameters for the energy level structure. This approach builds upon a theoretical model that includes effects of the static strain, dynamic Jahn-Teller coupling, and magnetic field and introduces two coupling rates, one each for the ground and the excited states, to characterize the combined effects of strain and Jahn-Teller coupling. With the use of an analytical expression for the energy level structure of the SiV center under a transverse magnetic field, these two coupling rates can be directly derived from the measurement of the frequency separation between two spin-conserved transitions in a photoluminescence excitation spectrum and the measurement of the coherent population trapping resonance related to the SiV ground spin states. Additional experimental studies on the dependence of the energy level structure on the magnetic field amplitude and direction further verify the theoretical model and reveal contributions from unequal orbital magnetic coupling for the ground and excited states.