Entanglement between nitrogen vacancy spins in diamond controlled by a nanomechanical resonator

TL;DR

This paper proposes a novel nano-electromechanical resonator design that uses magnetic field-induced cantilever deflection to control entanglement between nitrogen vacancy spins in diamond, potentially enhancing coupling strength.

Contribution

It introduces a new resonator mechanism based on magnetic deflection to control NV spin entanglement, improving coupling strength over previous methods.

Findings

Coupling strength between NV spins can be significantly increased.

Magnetoelastic stress and magnetic torque effectively control cantilever deflection.

Theoretical model suggests feasible experimental implementation.

Abstract

We suggest a new type of nano-electromechanical resonator, the functionality of which is based on a magnetic field induced deflection of an appropriate cantilever that oscillates between nitrogen vacancy (NV) spins in daimond. Specifically, we consider a Si(100) cantilever coated with a thin magnetic Ni film. Magnetoelastic stress and magnetic-field induced torque are utilized to induce a controlled cantilever deflection. It is shown that, depending on the value of the system parameters, the induced asymmetry of the cantilever deflection substantially modifies the characteristics of the system. In particular, the coupling strength between the NV spins and the degree of entanglement can be controlled through magnetoelastic stress and magnetic-field induced torque effects. Our theoretical proposal can be implemented experimentally with the potential of increasing several times the coupling strength between the NV spins as compared to the maximal coupling strength reported before in P. Rabl, et al. Phys. Rev. B 79, 041302(R) (2009).