ELECTRIC FIELD SENSING USING SINGLE SPIN MAGNET HYBRID SYSTEM
thesisposted on 2021-12-20, 13:47 authored by Wenqi TongWenqi Tong
Quantum sensing, a protocol that takes advantage of the extreme sensitivity of quantum systems to their environment, enables many applications of quantum systems for sensing. Inspired by direct electric field sensing using the Stark effect of a nitrogen-vacancy(NV) center, this work implements an NV-magnet hybrid way to explore the possibilities of overcoming NV’s relatively weak coupling strength to electric fields. The magnetic-noise-induced population relaxation of the NV center serves as the mechanism for sensing. Within this scheme, the magnetic noise spectrum is tuned by modulating the magnetic properties via voltage-controlled magnetic anisotropy (VCMA) or electric-field-induced magnetoelastic effect. In this way, the noise carrying the information of the electric field is taken as a signal - the shift of the noise spectrum leads to a population difference of NV energy levels, which is used for evaluating electric fields. The investigation of the relation between sensitivities and operation points reveals that lower operation frequency is desirable for better performance. The comparison between VCMA and electric-field-induced magnetoelastic effect indicates that the efficiency of converting electric field into magnetic property modulation is a critical parameter for sensitivity enhancement.