Abstract

Quantum computing and quantum sensing represent two distinct frontiers of quantum information science. In this work, we harness quantum computing to solve a fundamental and practically important sensing problem: the detection of weak oscillating fields with unknown strength and frequency. We present a quantum computing enhanced sensing protocol that outperforms all existing approaches. Furthermore, we prove our approach is optimal by establishing the Grover-Heisenberg limit -- a fundamental lower bound on the minimum sensing time. The key idea is to robustly digitize the continuous, analog signal into a discrete operation, which is then integrated into a quantum algorithm. Our metrological gain originates from quantum computation, distinguishing our protocol from conventional sensing approaches. Indeed, we prove that broad classes of protocols based on quantum Fisher information, finite-lifetime quantum memory, or classical signal processing are strictly less powerful. Our protocol is compatible with multiple experimental platforms. We propose and analyze a proof-of-principle experiment using nitrogen-vacancy centers, where meaningful improvements are achievable using current technology. This work establishes quantum computation as a powerful new resource for advancing sensing capabilities.

Personal information

Richard Allen is a PhD student in the Center for Theoretical Physics at MIT, where he is advised by Soonwon Choi. He is interested in quantum information theory, especially learning properties of quantum states and Hamiltonians and building new connections between quantum sensing and quantum algorithms and complexity. He completed his undergraduate study at Harvard University in physics, mathematics, and computer science and was previously a student researcher at Google Quantum AI. He is currently visiting the University of Oxford, where he is supported by a Marshall Scholarship.