Investigating coherence of electrons on helium with cavity quantum electrodynamics

用腔量子电动力学研究氦上电子的相干性

• 批准号: 1906003
• 负责人: Peter Littlewood
• 金额: $ 51万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1906003&HistoricalAwards=false
• 关键词: Investigating; coherence; electrons; helium; cavity

Non-technical abstractElectrons have a unique interaction with liquid helium. Like mythological Narcissus, they are attracted to their own image, but they are prevented from entering the liquid. The competing forces, along with the quantum fluctuations cause the electrons to levitate several nanometers above the surface, where they form a pristine two-dimensional electron gas. The electrons are manipulated using electrodes underneath the surface to control their motion and eventually their spin. The electrons are promising candidates as qubits for quantum information processors and the research team is also investigating unique quantum many-body states they form known as Wigner molecules. Despite being one of the first discovered two-dimensional electron systems,there have been no detections or other studies of their spin properties. The team is using recently developed single electron motion and spin resonance techniques to perform these fundamental measurements. The project is developing a unique hybrid quantum system, in which electrons on helium interact with high finesse superconducting circuits, that can manipulate both single electrons and microwave photons.Technical DescriptionElectrons on helium present unique opportunities to study the dynamics individual electrons, their spins, and the excitations of superfluid thin films. This research will explore the extreme mobility and long coherence of this two-dimensional electron system using a novel cavity QED based architecture. This allows the project to leverage the past decade worth of advances in service of quantum information to study the fundamental excitations of this system. Similarly, electrons on helium themselves may have properties uniquely well-suited to quantum information and sensing applications. The motion of an electron on helium is very analogous to that of a superconducting qubit, so many of the same techniques can be used to interrogate them, which should allow coherent manipulation of their motion for the first time. This would be a unique type of cavity QED system that would allow one to gain insight into the properties and interactions of this unique two-dimensional electron system. The project is attempting to detect and achieve strong coupling to a single trapped electron. In addition, the team will build Wigner molecules by adding or removing individual electrons to a pool of helium. A single electron on helium will be trapped and coupled to the superconducting cavity. Calculations predict that this system will reach the strong coupling limit of cavity quantum electrodynamics (QED) where the electron can interact coherently with single photons. This is the first investigation of coherent properties of an isolated electron on helium. The spin properties of a single trapped electron are also being studied, and it appears possible that it too may reach the strong-coupling limit, where the spin-photon coupling exceeds the all relevant decoherence rates, and single photon storage and manipulation become possible. Measurements of the spin coherence times will reveal information about the magnetic environment as well as the electron-helium interactions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术抽象电信与液氦具有独特的相互作用。像神话般的水仙一样，它们被自己的形象所吸引，但阻止了他们进入液体。竞争力以及量子波动会导致电子在表面上方的几种纳米悬浮，在那里它们形成原始的二维电子气体。使用表面下方的电极操纵电子，以控制其运动并最终旋转。这些电子作为量子信息处理器的Qubits有希望的候选者，研究团队还研究了它们形成的独特量子多体状态，称为Wigner分子。尽管是最初发现的二维电子系统之一，但仍未检测到其自旋特性。该团队正在使用最近开发的单电子运动和自旋共振技术来执行这些基本测量。该项目正在开发一个独特的混合量子系统，其中氦气上的电子与高技巧的超导电路相互作用，可以操纵单电子和微波光子。氦气上的技术描述纤维源是研究动态单个电子，其旋转以及超纤维薄膜的兴奋的独特机会。这项研究将使用基于QED的新型架构探索该二维电子系统的极端移动性和长期连贯性。这使得该项目能够利用过去十年的量子信息的进步，以研究该系统的基本激励。同样，氦气上的电子可能具有独特的特性，非常适合量子信息和传感应用。电子在氦气上的运动与超导量子的运动非常类似，因此可以使用许多相同的技术来审问它们，这应该可以首次连贯地操纵其运动。这将是一种独特的腔QED系统，它将允许人们深入了解这种唯一的二维电子系统的性质和相互作用。该项目正在尝试检测并实现与单个捕获电子的强耦合。此外，团队将通过将单个电子添加或去除氦池来构建Wigner分子。氦上的单个电子将被困并耦合到超导腔。计算预测，该系统将达到腔量子电动力学（QED）的强耦合极限，其中电子可以与单个光子一致相互作用。这是对氦气中分离电子的相干性能的第一个研究。还研究了单个捕获电子的自旋特性，并且似乎也有可能达到强耦合极限，而自旋光子耦合超过了所有相关的脱碳速率，并且单个光子的存储和操作变得可能。旋转相干时间的测量结果将揭示有关磁环境以及电子相互作用的信息。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被视为值得通过评估来获得支持。

项目成果

Single electrons on solid neon as a solid-state qubit platform

固体氖上的单电子作为固态量子位平台

• DOI: 10.1038/s41586-022-04539-x
• 发表时间: 2022
• 期刊: Nature
• 影响因子: 64.8
• 作者: Zhou, Xianjing;Koolstra, Gerwin;Zhang, Xufeng;Yang, Ge;Han, Xu;Dizdar, Brennan;Li, Xinhao;Divan, Ralu;Guo, Wei;Murch, Kater W.
• 通讯作者: Murch, Kater W.