One-step Realization of a Cross-Kerr Nonlinearity Between Two Ensembles of NV Centers via a Superconducting Flux Qubit

Abstract

Cross-Kerr nonlinearity has many important applications in quantum computation and quantum information processing. Here, we propose a one-step method to realize a cross-Kerr nonlinearity between two nitrogen-vacancy center ensembles (NV ensembles). The realization of cross-Kerr nonlinearity is based on a superconducting flux qubit dispersively coupled to two NV ensembles. Numerical simulations show that this cross-Kerr nonlinearity can be high-fidelity constructed a two-qubit controlled phase gate of NV ensembles.