CAREER: Topological Excitations in Two Dimensional Systems

这是一个颁发给女性科学家的职业奖。研究了二维电子系统中以空间扩展准粒子形式发生的特殊类型的电子激发。根据这些激励是否具有非零圈数或捻度来对它们进行分类通常是有利的。具有扭转的激发被称为“拓扑激发”，包括孤子、漩涡、畴壁和位错。它们不能衰变，就像你不拿起接收器就不能解开电话线一样：激励或绕组只能通过整个系统的大规模重新定向来消除。这转化为长期的稳定性，证明了在跨大陆光纤链路中使用被称为孤子的拓扑激励作为信号载体。拓扑激励的概念在物理学中被证明是非常有用的：与其试图描述整个系统的行为，一种更易于管理的方法只关注这些激励的稳定配置。因此，对风暴中的龙卷风、晶体中的位错或铁磁体中的畴壁进行了研究，以获得有关系统的大量信息。这一建议详细的广泛研究拓扑激励发生在二维电子系统在磁场。这是颁发给女科学家的职业成就奖。该研究涉及被称为拓扑激励的特殊类型的电子激励。这些激发态具有一种扭曲，就像螺丝钉一样。以前被认为是数学上的奇怪现象，最近在自然界的二维半导体结构中发现了它们，被称为量子霍尔系统。这些稳定的激发不仅仅是许多体电子相互作用的一种新语言，它们是真实的空间扩展准粒子。本建议的实验目标是更好地理解拓扑激励在二维电子系统中的作用。本CAREER建议的第二个重点是将通常用于入门级的新颖教学方法应用于高级物理课程。虽然这些新技术使入门物理教育受益，但在更高级的本科材料中却很少应用。我们的计划是将基于概念的问题与小组学习技术结合到更高级的课程中，并通过开发概念问题网站来促进这种引入。

Murphy 9733949 This is a CAREER Award to a female scientist. The research deals with special types of electronic excitations which occur as spatially extended quasiparticles in two-dimensional electron systems. It is often advantageous to sort such excitations according to whether or not they have a non-zero winding number or twist. Excitations possessing a twist are known as "topological excitations" and include solitons, vortices, domain walls and dislocations. They cannot decay for the same reason you cannot untwist a phone cord without picking up the receiver: the excitation or winding can only be removed by a large scale reorientation of the entire system. This translates to long term stability as evidenced by the use of a topological excitation known as a soliton as a signal carrier in transcontinental fiber links. The concept of a topological excitation has proven exceptionally useful in physics: Rather than attempt to describe the behavior of the entire system, a more manageable approach focuses on just the stable configuration of these excitations. Thus the tornadoes in a storm, the dislocations in a crystal or the domain walls in a ferromagnet are studied to obtain a great deal about the system at hand. This proposal details an extensive study of the topological excitations occurring on two-dimensional electronic systems in a magnetic field. %%% This is CAREER Award to a female scientist. The research deals with special types of electronic excitations known as topological excitations. These excited electron states possess a kind of twist, like a screw. Previously studied as mathematical oddities, they have recently been found in nature in two-dimensional semiconductor structures, known as Quantum Hall systems. These stable excitations are more than a new language for many body electron interactions, they are real spatially extended quasiparticles. The experimental goal of this proposal is a greater understanding of the role of topological excitations in two dimensional electronic systems. The second focus of this CAREER proposal is the adaptation of novel instructional approaches, commonly used at the introductory level, to upper level physics courses. While introductory physics education has benefited from these new techniques, there has been little application to more advanced undergraduate material. The plan is to introduce concept based questions in conjunction with group learning techniques into the more advanced curricula and to facilitate this introduction by the development of a concept question website.