# Arbitrary Control of Entanglement between two nitrogen-vacancy center ensembles coupling to superconducting circuit qubit

## TL;DR

This paper presents a scheme for controlling entanglement between nitrogen-vacancy center ensembles coupled to a superconducting circuit, enabling generation of various complex entangled states with robustness against decoherence.

## Contribution

It introduces a scalable, cavity-decay-insensitive method for producing arbitrary multi-particle entangled states in a hybrid quantum system.

## Key findings

- Successfully generates NOON, N-dimensional, and entangled coherent states.
- Analysis shows robustness against cavity decay and spontaneous emission.
- Numerical simulations confirm feasibility with current technology.

## Abstract

We propose an effective scheme for realizing a Jaynes-Cummings (J-C) model with the collective nitrogen-vacancy center ensembles (NVE) bosonic modes in a hybrid system. Specifically, the controllable transmon qubit can alternatively interact with one of the two NVEs, which results in the production of $N$ particle entangled states. Arbitrary $N$ particle entangled states, NOON states, N-dimensional entangled states and entangled coherent states are demonstrated. Realistic imperfections and decoherence effects are analyzed via numerical simulation. Since no cavity photons or excited levels of the NV center are populated during the whole process, our scheme is insensitive to cavity decay and spontaneous emission of the NVE. The idea provides a scalable way to realize NVEs-circuit cavity quantum information processing with current technology.