This perspective reviews recent progresses in the generation of metrologically useful atomic entangled states with neutral atom array and illustrate a future blueprint for the optimal metrology.
Arrays of alkaline-earth atoms offer optical-clock qubits with long coherence times, scalability to large qubit numbers, and tunable Rydberg-mediated interactions. These features provide an ideal setting for exploring how microscopic control and entanglement can improve the performance of optical atomic clocks beyond conventional limits. This talk will cover two efforts in this area: recent results from JILA demonstrating entanglement-enhanced optical-clock operation, and a brief introduction to a new effort at Caltech towards next-generation quantum metrology with neutral-atom arrays.
Quantum technologies exploit entanglement to revolutionize computing, measurement, and communication. This has stimulated the research in different areas of physics to engineer and manipulate fragile many-particle entangled states. Progress has been particularly rapid for atoms. Thanks to the large and tunable nonlinearities and the well developed techniques for trapping, controlling and counting, many groundbreaking experiments have demonstrated the generation of entangled states of trapped ions, cold and ultracold gases of neutral atoms. Moreover, atoms can couple strongly to external forces and light fields, which makes them ideal for ultra-precise sensing and time keeping. All these factors call for generating non-classical atomic states designed for phase estimation in atomic clocks and atom interferometers, exploiting many-body entanglement to increase the sensitivity of precision measurements. The goal of this article is to review and illustrate successful theoretical proposals and experiments with atomic ensembles that have demonstrated many-particle entanglement and quantum-enhanced metrology.
Entanglement-enhanced quantum metrology explores the utilization of quantum entanglement to enhance measurement precision. When particles in a probe are prepared into a suitable quantum entangled state, they may collectively accumulate information about the physical quantity to be measured, leading to an improvement in measurement precision beyond the standard quantum limit and approaching the Heisenberg limit. The rapid advancement of techniques for quantum manipulation and detection has enabled the generation, manipulation, and detection of multi-particle entangled states in synthetic quantum systems such as cold atoms and trapped ions. This article aims to review and illustrate the fundamental principles and experimental progresses that demonstrate multi-particle entanglement for quantum metrology, as well as discuss the potential applications of entanglement-enhanced quantum sensors.