Enhancement of spin-to-charge conversion of diamond NV centers at ambient conditions using surface electrodes

TL;DR

This paper introduces a surface electrode technique to enhance spin-to-charge conversion in diamond NV centers, significantly improving optical spin contrast at room temperature for quantum sensing applications.

Contribution

The study proposes a novel electrode-assisted method to increase spin contrast in NV centers, enabling higher fidelity spin readout under ambient conditions.

Findings

Predicted optical contrast of 42%, the highest at room temperature.

The method alters NV energy levels to improve spin-to-charge conversion.

Open new pathways for NV-based quantum sensing research.

Abstract

The nitrogen-vacancy (NV) center in diamond is a heavily studied defect due to its potential applications to quantum metrology and computation, particularly in ambient conditions. The key mechanism to using the NV in any application lies in the ability to read out the spin state of the defect which is typically done optically. The optical contrast is then the key metric for electron spin readout fidelity and one of the key limiting factors in the NV's overall performance. We present a new mechanism for high contrast readout using the spin-to-charge conversion (SCC) mechanism in conjunction with an electrode to improve the spin contrast by altering the NV energy levels relative to the diamond conduction band. Theoretical modelling predicts an optical spin contrast at 42% which would be the highest optical contrast for the NV at room temperature and the technique opens up a range of alternative research pathways for the NV which are discussed.