Universal Dynamics of Metrologically Useful Entanglement in Strongly Interacting, Disordered Many-Body Systems

Abstract

Controlling the dynamics of targeted quantum correlations is a central goal across many disciplines of quantum science. For applications in nanoscale quantum sensing, nitrogen-vacancy (NV) centers in diamond have recently emerged as a leading platform due to their atom-like nature, exquisite magnetic sensitivity and well-developed coherent control techniques under ambient conditions. However, harnessing the entanglement structure required to improve this sensitivity beyond the standard quantum limit (SQL) from the native dipolar interactions between NV centers is challenging due to their strong positional disorder, three-dimensional geometry and low-fidelity readout. Coupled tightly to proof of principle experimental demonstrations, this thesis provides a theoretical blueprint to realize practical, entanglement-enhanced quantum sensing in the solid-state via far-from-equilibrium dynamics of dense ensembles of NV centers in diamond. Our most fundamental contribution is to identify a universal mechanism exploiting the thermalization of long-wavelength spin textures to generate scalable spin squeezing in the absence of finite temperature symmetry breaking. We further develop a novel sensing protocol based on asymmetric time-reversal capable of rapidly breaking the SQL without high-fidelity readout. Challenging long-standing beliefs in the field, these results open the door to a new era of entanglement-enhanced sensing under ambient conditions, with applications ranging from nanoscale imaging of biological structures to covariance magnetometry of exotic quantum materials.