All‐Resonance Controlled‐Phase Gate on Two Nonlocal Nitrogen‐Vacancy Center Ensembles Assisted by a Superconducting Quantum Circuit

Abstract

The realization of universal quantum logical gates on nonlocal nitrogen‐vacancy center ensembles (NVEs) is a basic task for universal quantum computing with NVEs. In contrast to previous works on the construction of gates, a one‐step all‐resonance scheme is proposed to construct a controlled‐phase gate on two nonlocal NVEs that are coupled to different superconducting transmission line resonators connected by a superconducting transmon qubit. The gate can be easily realized using only one step. Moreover, the all‐resonance operation allows the gate to be achieved within a short time. By considering the feasible parameters obtained in the experiments, this gate can be completed within 101 ns with a high fidelity of approximately 97.8%, which has reached the threshold of fault‐tolerance quantum computing.