Quantum information processing using frequency control of impurity spins in diamond

TL;DR

This paper demonstrates frequency-based control of impurity spins in diamond NV centers for quantum information processing, enabling selective addressing and universal two-qubit gates using RF and optical fields, advancing scalable quantum computing.

Contribution

It introduces a novel frequency control method for NV center spins and shows how combined RF and optical fields can implement universal quantum gates.

Findings

Frequency control allows selective addressing of NV centers.

Optical fields enable controlled coupling for two-qubit gates.

Combined RF and optical control supports scalable quantum architectures.

Abstract

Spin degrees of freedom of charged nitrogen-vacancy (NV$^-$) centers in diamond have large decoherence times even at room temperature, can be initialized and read out using optical fields, and are therefore a promising candidate for solid state qubits. Recently, quantum manipulations of NV$^-$- centers using RF fields were experimentally realized. In this paper we show; first, that such operations can be controlled by varying the frequency of the signal, instead of its amplitude, and NV$^-$- centers can be selectively addressed even with spacially uniform RF signals; second, that when several \NV - centers are placed in an off-resonance optical cavity, a similar application of classical optical fields provides a controlled coupling and enables a universal two-qubit gate (CPHASE). RF and optical control together promise a scalable quantum computing architecture.