Quantum Measurement Theory Applied to Cold Atoms

我的研究涉及冷原子理论，冷原子是指被冷却到绝对零度之上的百万分之一以下的原子。冷原子具有非凡的性质：在如此低的温度下，它们的行为像波(波-粒子二元性)，可以形成新的物质状态，如玻色-爱因斯坦凝聚体(BEC)，其中所有原子共享完全相同的量子态，并形成巨大的宏观物质波-量子世界的海啸。这意味着通常局限于微观尺度的量子现象被放大到宏观尺度。有了这笔发现奖，我建议使用冷原子来尝试解决为什么我们在宏观世界中通常看不到量子波干扰的悖论。这就是众所周知的量子测量问题，我计划在两个空间分离的陷阱中的BEC中研究它，这样，根据量子力学，每个原子同时在两个地方！这项工作具有技术含义：目前正在密集开发的设备，如量子计算机，需要在面临热环境的有害影响时保持量子干涉，而冷原子是试图抵消这些热效应的量子控制技术的非常通用的试验台。

My research concerns the theory of cold atoms, which are atoms that have been cooled down to temperatures below one millionth of one degree above absolute zero. Cold atoms have remarkable properties: at such low temperatures they behave like waves (wave-particle duality) and can form new states of matter such as Bose-Einstein condensates (BECs) where all the atoms share exactly the same quantum state and form giant macroscopic matter waves - the tsunamis of the quantum world. This means that quantum phenomena that are normally confined to microscopic scales become amplified up to macroscopic ones. With this Discovery grant I propose to use cold atoms to try to resolve the paradox as to why we do not normally see the interference of quantum waves in our macroscopic world. This is known as the quantum measurement problem, and I plan to study it in BECs that are held in two spatially separated traps, so that, according to quantum mechanics, each atom is in two places at once! This work has technological implications: devices currently under intensive development, such as quantum computers, need to maintain quantum interference in the face of the deleterious effects of a thermal environment, and cold atoms make very versatile test-beds for quantum control techniques which attempt to counteract these thermal effects.