Harnessing Quantum Entanglement for Quantum-Enhanced Sensing through Interaction-Based Readout

Entanglement, a quantum phenomena whereby distinct parts of a system become inextricably linked and cannot be physically described independently, is a key resource in the development of new quantum-enhanced technologies that promise astounding improvements in performance compared to current devices describable by the classical physics of Newton and Galileo. Examples include quantum-enhanced sensors that use entanglement to amplify small perturbations to quantum systems due to weak changes in gravity, electromagnetic fields or the surrounding environment, and which can have applications ranging from industry, where they can be used in searches for natural resources, to fundamental science, where they can enable ultra-precise searches for physics beyond the standard model.

Nevertheless, a key challenge in the frontier of quantum-enhanced sensing is the development of simple and practical ways to characterize these perturbations of entangled quantum systems. This research project seeks to understand how to overcome this problem by using "interaction-based readout" (IBR), wherein the complex dynamics induced by interactions between constituent particles of a quantum system is used as an intrinsic internal probe.

The work conducted will promote the progress of basic science, as developing realistic and robust IBR approaches which minimize technical challenges associated with using entangled quantum systems can be important for the realization of state-of-the-art sensors with real world applications. Moreover, the research provides valuable technical training opportunities for participating students and a post-doctoral researcher, contributing to the STEM workforce and economy.

The overall goal of the project is to establish a theoretical framework for optimal IBR schemes for quantum-enhanced sensing with simple measurement probes. This core intellectual task will be approached by investigation of IBR schemes in two inter-related topics: i) quantum sensing using entangled ground-states, and iii) chaotic quantum sensors. The first topic will seek to devise optimal IBR schemes to exploit entangled ground states generated by quasi-adiabatic evolution for quantum-enhanced metrology, taking into account realistic experimental limitations on control of measurements and dynamics, and identifying optimal regimes of operation that lead to a practical quantum advantage.

The latter topic studies how IBR can serve as an enabling tool to harness and characterize complex entangled states generated via many-body quantum chaos, with a core focus on developing strategies to overcome deleterious decoherence and technical noise that degrades entanglement. Developing an improved understanding of IBR schemes in these scenarios will have immediate impact by broadening the scope of non-equilibrium and quasi-equilibrium systems that can be practically exploited for quantum-enhanced sensing and technology.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.