Matterwave Interferometry with Ions

Matterwave 离子干涉测量

• 批准号: 1205736
• 负责人: Dallin Durfee
• 金额: $ 23.23万
• 依托单位: Brigham Young University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1205736&HistoricalAwards=false
• 关键词: Matterwave; Interferometry; Ions

One very bizarre thing that we learn from quantum mechanics is that it is possible for an object to be in a superposition of two or more states at once. For example, in our experiment we will use optical transitions driven by pairs of laser beams to put strontium ions into a superposition state in which the ion is essentially in two different places at the same time. Quantum mechanics also tells us, however, that if you look to see what state an object is in, the process of measuring will collapse the system into a single state. So, although we will be able to "split" ions and put them in two different physical locations at the same time, we will never be able to detect them at two different locations at the same time.The fact that we can never actually "see" the ions in two places at once might make it sound like there is no point in doing the experiment. But there is a trick to making this superposition useful. What we will do, as has been done in neutral atom interferometers, is to put the two pieces back together, such that each ion is in a single location, before measuring its state. When we put the pieces back together, the ions will "remember" things it felt at both of the locations they occupied when they were in the superposition state, and that "memory" will affect the internal state of the ions when the pieces are put back together again.Because ions are very sensitive to electric fields, the state that the ions end up in will be determined in part by the difference in the electrostatic potentials at the different locations that the ions experienced. Using laser fluorescence to probe the state of the ions at the end of the experiment, we should be able to detect electric fields with unprecedented precision. This will allow us to do fundamental tests of the laws of electromagnetism - to see if there are perhaps some subtle differences between nature's laws and our mathematical description of them. We will also be able to probe electric fields above surfaces coherently, allowing us to study things like scattering of electron pairs in superconductors.

我们从量子力学中学到的一件非常奇怪的事情是，一个物体有可能同时处于两种或多种状态的叠加。 例如，在我们的实验中，我们将使用由成对激光束驱动的光学跃迁将锶离子置于叠加态，其中离子基本上同时处于两个不同的位置。 然而，量子力学还告诉我们，如果你观察一个物体所处的状态，测量过程会将系统崩溃为单一状态。 因此，尽管我们能够“分裂”离子并将它们同时放置在两个不同的物理位置，但我们永远无法同时在两个不同的位置检测到它们。事实上，我们永远无法同时“看到”两个位置的离子，这可能会让听起来做这个实验没有意义。 但有一个技巧可以让这种叠加变得有用。我们要做的，就像在中性原子干涉仪中所做的那样，是将两部分重新组合在一起，使得每个离子在测量其状态之前都位于一个位置。 当我们将这些碎片放回一起时，离子会“记住”它们在处于叠加状态时所占据的两个位置所感受到的东西，并且当这些碎片再次放回一起时，这种“记忆”将影响离子的内部状态。因为离子对电场非常敏感，所以离子最终所处的状态将部分取决于离子所经历的不同位置的静电势的差异。 在实验结束时使用激光荧光探测离子的状态，我们应该能够以前所未有的精度检测电场。 这将使我们能够对电磁定律进行基本测试——看看自然定律和我们对它们的数学描述之间是否存在一些微妙的差异。 我们还能够相干地探测表面上方的电场，从而使我们能够研究超导体中电子对的散射等问题。