Probing electric-dipole-enabled transitions in the excited state of the nitrogen-vacancy center in diamond

TL;DR

This study reveals strong electric dipole transitions in the excited state of nitrogen-vacancy centers in diamond, enabling electric field control and improved coherence for quantum applications.

Contribution

It demonstrates resonant laser excitation and microwave electric field control of excited state orbitals, showing tunable dressed states and electric dipole effects in NV centers.

Findings

Strong transition dipoles in excited state orbitals

Tunable dressed states protected against electric field fluctuations

Electric dipole driving broadens microwave resonances

Abstract

The excited orbitals of color centers typically show stronger electric dipoles, which can serve as a resource for entanglement, emission tuning, or electric field sensing. Here, we use resonant laser excitation to expose strong transition dipoles in the excited state (ES) orbitals of the negatively charged nitrogen vacancy center in diamond. By applying microwave electric fields, we perform strong Rabi driving between ES orbitals, and show that the dressed states can be tuned in frequency and are protected against fluctuations of the transverse electric field. In contrast with previous results, we observe sharp microwave resonances between magnetic states of the ES orbitals, and find that they are broadened due to simultaneous electric dipole driving.