基于超冷原子体系的多体量子干涉与精密测量

High controllability and robust quantum coherence of ultracold atomic systems offer new challenges and opportunities to explore many-body quantum physics and build practical quantum devices. Many-body quantum interferometry is not only the basic tool to test quantum coherence in many-body systems, but also the physical base for many-body quantum interference devices and quantum precision measurements. By using both analytical and numerical approaches, this research project aims to study many-body quantum interferometry and precision measurement with ultracold atomic systems. We will consider three typical physical systems: (1) an ensemble of Bose condensed atoms involving multiple internal hyperfine states or external motional states, (2) ultracold alkaline-earth-like atoms in optical lattices (optical lattice clock system), and (3) an array of ultracold ions in a linear Paul trap. We will invetigate the application of quantum entanlgment in precision measurement and the environment effects on measurement outcome. In particular, we will study the following problems: how to improve measurement precision via quantum entanglement, how to prepare entangled quantum states for high-precision quantum inteferometry, and how environment effects such as decoherence and dissipation affect implementation efficiency/robustness and measurement outcomes. We will also develop innovative numerical approach for simulating dynamical behavior in many-body quantum interferometry process and these numerical simulation methods will be helpful to simulate many-body quantum dynamics and find possible method for controlling these many-body quantum dynamics.

超冷原子体系的高度可控性和稳固的量子相干性为研究多体量子物理和制造实用量子器件提供了新的挑战与机遇。多体量子干涉是检验多体量子体系相干性的基本手段，也是多体量子相干器件和量子精密测量的物理基础。理论分析结合数值模拟，本项目将研究基于超冷原子体系的多体量子干涉与精密测量。主要的研究体系包括：（1）涉及多个超精细态或质心运动模式的玻色凝聚原子系综，（2）光晶格中的超冷碱土金属原子（光晶格原子钟）；（3）线性Paul阱中的超冷离子阵列。我们将探索多体量子纠缠在精密测量中的应用和环境效应对测量结果的影响，具体包括：如何利用量子纠缠提高测量精度，如何制备干涉所需的量子纠缠态，如何利用制备的量子纠缠态进行干涉，褪相干和耗散等环境效应怎样影响测量方案的稳定性和测量精度。同时，我们将发展有效的数值模拟方法分析多体量子干涉过程中的动力学现象，这些数值模拟方法将有助于研究多体量子体系的动力学演化和调控。

本项目通过理论分析结合数值模拟的方法，主要研究了基于超冷原子体系的多体量子干涉、精密测量等方面涉及到的一些关键物理问题。在涉及多个超精细态或质心运动模式的玻色凝聚原子系综、光晶格、超冷离子阵列等量子体系中，我们探索了多体量子纠缠在精密测量中的应用，包括：如何利用量子纠缠提高测量精度，如何制备干涉所需的量子纠缠态，如何利用制备的量子纠缠态进行干涉，褪相干和耗散等环境效应怎样影响测量方案的稳定性和测量精度等。同时，我们发展了我们发展了有效的数值模拟及解析的方法，分析和揭示了一些新奇的多体量子动力学现象，这些解析与数值模拟方法也将有助于研究多体量子体系的动力学演化和调控，探索多体量子干涉及精密测量的新方案。本项目按计划顺利完成，达到了预期的研究目标。