Physics of Confined Electrons and Electron Spins on Liquid Helium

* 非技术摘要 * 电子是所有原子的基本组成部分，它们之间的相互作用可以采取各种各样的形式，这在很大程度上是我们在周围世界看到的各种材料属性的主要原因。 这个实验项目旨在更多地了解电子之间相互作用的表现方式。 电子的运动和状态由量子力学控制，但在特殊情况下，经典牛顿物理学提供了一个很好的近似。 在一组实验中，少数电子将逐渐被迫使越来越靠近，以增加量子力学效应的重要性，并了解这如何影响它们的相互作用。 除了带负电荷外，每个电子的作用都像极弱的条形磁铁。 另一组实验将研究这些“磁矩”在电子聚集在一起时如何相互作用。 这部分项目的一个重要目标是开发一种测量单个电子磁矩方向的方法。展示这种能力是构建使用单个电子磁矩作为其比特的量子计算机的重要一步。 该项目将支持博士教育。学生，与本科研究人员的参与，在基础物理学和它的应用程序之间的边界工作，以新的技术机会。 这些学生将学习如何使用现代纳米科学研究的最先进的工具，这已被证明是在学术界和高科技行业的职业生涯的优秀培训。技术摘要 * 这个个人研究者奖支持一个项目，该项目将使用漂浮在超流氦表面的电子来研究量子点结构中电子-电子相互作用和自旋弛豫和退相干中量子效应的开始。 将开发亚微米结构（点），以将电子紧紧限制在小团簇中的氦上，并测量连续添加电子的能量。 这些实验将利用最近的发展，可靠地移动单个电子穿过氦表面，以测量点外部的电子，而不是在传感结构扭曲电位的点内。 具有两个被捕获电子的类似点结构的总能量将取决于它们的相对自旋，单重态低于三重态。 将测量可实现的单重态-三重态分裂，并为大分裂优化结构。 通过仔细研究特定自旋态持续存在的时间尺度，预计能够确定电子自旋弛豫和退相干时间。 测量单电子自旋及其退相干的能力是实现电子自旋量子计算机的关键步骤。 这项研究将由一位博士进行。学生和兼职本科生。 学生将学习纳米纤维，低温技术和实验端的高灵敏度测量，以及多体量子系统和量子信息的理论。 这些技能，需要足智多谋和关注细节，已被证明是在学术界和高科技行业的科学职业生涯的优秀培训。

****NON-TECHNICAL ABSTRACT****Electrons are a fundamental constituent of all atoms, and it is the tremendous variety of forms their interactions can take that is largely responsible for the wide range of material properties we see in the world around us. This experimental project is aimed at understanding more about the ways in which interactions between electrons manifest themselves. The motion and states of the electrons are governed by quantum mechanics, but under special circumstances classical Newtonian physics provides a good approximation to their behavior. In one set of experiments a small number of electrons will gradually be forced closer and closer together to increase the importance of quantum mechanical effects, and to understand how that affects their interactions. In addition to having a negative electric charge, every electron also acts like an extremely weak bar magnet. Another set of experiments will study how these "magnetic moments" interact as the electrons are brought together. An important aim of this part of the project is to develop a way to measure the orientation of the magnetic moment of a single electron. Demonstrating this capability represents an important step towards constructing a quantum computer that uses the magnetic moments of individual electrons as its bits. This project will support the education of a Ph.D. student, together with the participation of undergraduate researchers, working at the boundary between fundamental physics and its applications to new technological opportunities. These students will learn how to use the most advanced tools of modern nanoscience research, which has proven to be excellent training for careers in both academia and high technology industries.****TECHNICAL ABSTRACT****This individual investigator award supports a project that will use electrons floating on the surface of superfluid helium to study the onset of quantum effects in electron-electron interactions and spin relaxation and decoherence in quantum dot structures. Submicron structures (dots) will be developed to tightly confine electrons on the helium in small clusters, and the energy to successively add electrons will be measured. These experiments will take advantage of recent developments in reliably moving individual electrons across the helium surface to measure electrons outside the dot, rather than within the dot where the sensing structures distort the potentials. The total energy in similar dot structures with two trapped electrons will depend upon their relative spins, with singlet states lying lower than triplets. Measurements of the achievable singlet-triplet splitting will be made, and structures optimized for large splitting. By careful study of the time scales over which particular spin states persist it is expected to be able to determine the electron spin relaxation and decoherence times. The ability to measure single electron spins and their decoherence are key steps on the road to implementing an electron spin quantum computer. This research will be performed by a Ph.D. student and part-time undergraduate students. The students will learn nanofabrication, low-temperature techniques, and high-sensitivity measurements on the experimental end, and about the theory of many-body quantum systems and quantum information. These skills, requiring resourcefulness and attention to detail have proven themselves to be excellent training for scientific careers in academia and high technology industries.