Experiments on the Role of Disorder in the Quantum Phases and Phase Transitions of Two-Dimensional Electrons

技术：半导体异质结构中的二维电子系统（2DES）一直是新物理现象的温床，表现出强关联物理，也是新理论思想的试验场。 在过去，对该系统的物理研究主要集中在理想清洁系统的相关物理学上，并且实验已经在当时可达到的最高流动性的2DES上设计和进行。 这项研究将集中在三种新的材料/器件结构，以访问以前无法访问的物理制度的稀释2DES可控可调的混乱。 直流传输和微波光谱测量将在低T下降到核退磁冰箱的温度范围内寻找预期的新阶段的电子物质中间的维格纳晶体在干净的2DES和安德森绝缘体在高度无序的2DES。 它将在凝聚态物理学和半导体材料科学方面教育学生。 他们将配备实验低温物理技术和半导体器件加工技术的实践专家。 非技术性：在现代电子学中，几乎所有的设备功能都是由电子执行的，这些电子被限制在半导体的薄膜中或沿着界面移动。 这种所谓的半导体中的二维电子，虽然在正常环境下表现为带电粒子的普通气体，但在适当设计的实验条件下，已经成为新物理现象的温床，表现出强关联电子的量子物理学，以及新理论思想的试验场。 这项研究将调查在所有半导体中不可避免的无序的影响，并探索一种新的物理机制，在这种机制中，无序和电子相关之间的相互作用有望产生电子物质的新阶段。 该研究是多学科的性质;它将教育学生流利的凝聚态物理学和半导体材料科学，并为他们提供实验低温物理技术和半导体器件加工技术的实践经验。

Technical:The two-dimensional electron systems (2DES) in semiconductor heterostructures has been a hot bed for new physical phenomena, manifesting strong correlation physics, and a testing ground for novel theoretical ideas. Physics research on the system has in the past mostly focused on the correlation physics of ideally clean systems and the experiments have been designed and carried out on 2DES with the highest mobility attainable at the time. This research will focus on three new material/device structures to access previously inaccessible physical regimes of dilute 2DES with controllably tunably disorder. DC transport and microwave spectroscopy measurements will be made at low T down to the nuclear demagnetization refrigerator temperature range to search for the expected new phases of electron matter intermediate to the Wigner crystal in clean 2DES and the Anderson insulator in highly disordered 2DES. It will educate students in condensed-matter physics and the science of semiconductor materials. They will be equipped with hands-on expertize in experimental low temperature physics techniques and semiconductor device processing technology. Non-Technical:In modern day electronics, almost all device functions are performed by electrons that are confined to move in thin films, or along the interfaces, of semiconductors. Such so-called two-dimensional electrons in semiconductors, though behaving at normal ambient as an ordinary gas of charged particles, have been under properly designed experimental conditions a hot bed for new physical phenomena, manifesting the quantum physics of strongly correlated electrons, and a testing ground for novel theoretical ideas. This research will investigate the influence of disorder, which is inevitable in all semiconductors, and explore a new physical regime, where the interplay between disorder and electron correlation is expected to give rise to new phases of the electron matter. The research is multidisciplinary in nature; it will educate students to be fluent in condensed-matter physics and the science of semiconductor materials, and equip them with hands-on expertize in experimental low temperature physics techniques and the processing technology of semiconductor devices.