Excited-state spectroscopy using single-spin manipulation in diamond

TL;DR

This study employs single-spin resonant spectroscopy to analyze the spin structure of the excited state in diamond NV centers at room temperature, revealing key differences from the ground state that impact quantum applications.

Contribution

It provides detailed measurements of the excited state spin levels, including zero-field splitting, g-factor, and hyperfine interactions, and explores how local strain affects spin properties.

Findings

Excited state zero-field splitting is about half of the ground state.

Hyperfine splitting in the excited state is ~20 times larger.

Spin-splitting varies between NV centers, influenced by local strain.

Abstract

We use single-spin resonant spectroscopy to study the spin structure in the orbital excited-state of a diamond nitrogen-vacancy center at room temperature. We find that the excited state spin levels have a zero-field splitting that is approximately half of the value of the ground state levels, a g-factor similar to the ground state value, and a hyperfine splitting ~20x larger than in the ground state. In addition, the width of the resonances reflects the electronic lifetime in the excited state. We also show that the spin-splitting can significantly differ between NV centers, likely due to the effects of local strain, which provides a pathway to control over the spin Hamiltonian and may be useful for quantum information processing.