First- and second-order gradient couplings to NV centers engineered by the geometric symmetry

TL;DR

This paper explores how engineered magnetic field gradients from nanowires with specific geometries can create first- and second-order couplings to NV centers, enabling advanced quantum interactions and potential sensing applications.

Contribution

It demonstrates the design of nanowire geometries to control magnetic gradient couplings to NV centers, including Jaynes-Cummings and second-order interactions.

Findings

Straight nanowires enable Jaynes-Cummings spin-phonon coupling.

Parallel nanowires induce second-order magnetic gradients for spin-phonon interactions.

Potential applications in quantum measurement and sensing are supported.

Abstract

The magnetic fields with the first- and second-order gradient are engineered in several mechanically controlled hybrid systems. The current-carrying nanowires with different geometries can induce a tunable magnetic field gradient because of their geometric symmetries, and therefore develop various couplings to nitrogen-vacancy (NV) centers. For instance, a straight nanowire can guarantee the Jaynes-Cummings (JC) spin-phonon interaction and may indicate a potential route towards the application on quantum measurement. Especially, two parallel straight nanowires can develop the coherent down-conversion spin-phonon interaction through a second-order gradient of the magnetic field, and it can induce a bundle emission of the antibunched phonon pairs via an entirely different magnetic mechanism. Maybe, this investigation is further believed to support NV's future applications in the area of quantum manipulation, quantum sensing, and precision measurement, etc.