Multifrequency spin resonance in diamond

TL;DR

This paper investigates the behavior of nitrogen-vacancy centers in diamond under strong, multifrequency excitation beyond the rotating wave approximation, revealing complex phenomena like multiphoton transitions and informing quantum spin manipulation techniques.

Contribution

It provides new insights into spin dynamics under strong multifrequency excitation, combining experimental observations with theoretical analysis beyond traditional approximations.

Findings

Observation of multiphoton transitions

Identification of coherent destruction of tunneling

Analysis of spin response beyond rotating wave approximation

Abstract

Magnetic resonance techniques provide a powerful tool for controlling spin systems, with applications ranging from quantum information processing to medical imaging. Nevertheless, the behavior of a spin system under strong excitation remains a rich dynamical problem. In this paper, we examine spin resonance of the nitrogen-vacancy center in diamond under conditions outside the regime where the usual rotating wave approximation applies, focusing on effects of multifrequency excitation and excitation with orientation parallel to the spin quantization axis. Strong-field phenomena such as multiphoton transitions and coherent destruction of tunneling are observed in the spectra and analyzed via numerical and analytic theory. In addition to illustrating the response of a spin system to strong multifrequency excitation, these observations may inform techniques for manipulating electron-nuclear spin quantum registers.