Two-Dimensional Electrons on Helium

氦上的二维电子

• 批准号: 9701428
• 负责人: Arnold Dahm
• 金额: $ 35.45万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 2001-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9701428&HistoricalAwards=false
• 关键词: Two; Dimensional; Electrons; Helium

9701428 Dahm This is a renewal project covering four areas in the study of electrons on liquid helium. We propose a new route to the ripplonic-polaron state, which consists of an electron self- trapped in a surface dimple. We suggest that ripplon-induced weak localization of the electron occurs in the weak scattering limit. As the scattering, controlled by the holding electric field, is increased, a transition to the bound polaron will occur with possibly strong localization as a precursor to the bound state. The mobility of electrons in the low density limit will be studied as a function of holding field, magnetic field, and temperature. We will attempt to observe weak localization by thermal ripplons and the bound polaron state. We further propose to study plasma oscillations of quasi-one-dimensional electron gas formed by confining electrons to helium filled grooves in an insulating substrate. We will also search for viscoelastic modes in the electron fluid and study the pinned electron solid as a function of coupling to pinning centers. %%% This a renewal project to study electrons bound to a liquid helium surface. In such a situation, the bound electrons form a single layer which floats on the surface of helium. This system is the simplest two-dimensional system. It has interesting physical properties and some of its properties are analogs of those which occur in three-dimensional (3D) systems. The parameters controlling these analogs can be varied through a wider range and are more easily controlled than in three dimensions. We propose to study electrons on a helium surface in an attempt to better understand the physics of systems of lower dimensions and the physics of 3D systems which are difficult to probe. Our study will include the spatial localization of electrons by random scattering, analogous to the localization of electrons in some 3D semiconductors. By increasing the scattering rate we expect to find electrons trapped in surface depressions, an analog of electrons trapped in a highly compressible lattice in 3D. We will study the pinned electron crystal which is an analog of 3D sliding charge-density waves. We also propose to study sound in a single rows of electrons in an attempt to understand the physics of one-dimensional systems. ***

小行星9701428 这是一个更新项目，涵盖了液氦电子研究的四个领域。 我们提出了一种新的路径，它由一个电子自陷在表面凹坑的涟漪极化子状态。 我们认为，在弱散射极限下，电子会发生涟波诱导的弱局域化。 随着由保持电场控制的散射的增加，将发生到束缚极化子的跃迁，并可能发生强烈的局部化，作为束缚态的前体。 在低密度极限的电子迁移率将作为一个功能的保持场，磁场和温度进行研究。 我们将尝试观察热涟波和束缚极化子态的弱定域化。 我们进一步提出研究等离子体振荡的准一维电子气形成的限制电子氦填充的凹槽中的绝缘基板。 我们也将寻找电子流体中的黏弹性模式，并研究被钉扎电子固体与钉扎中心耦合的函数。 这是一个研究电子束缚在液氦表面的更新项目。 在这种情况下，束缚的电子形成一个单层，漂浮在氦的表面。 这个系统是最简单的二维系统。 它具有有趣的物理性质，并且它的一些性质类似于在三维（3D）系统中发生的那些性质。 控制这些类似物的参数可以在更宽的范围内变化，并且比三维更容易控制。 我们建议研究氦表面上的电子，以更好地理解低维系统的物理和难以探测的3D系统的物理。 我们的研究将包括通过随机散射的电子的空间定位，类似于某些3D半导体中的电子定位。 通过增加散射率，我们期望发现电子被捕获在表面 凹陷，在3D中被捕获在高度可压缩晶格中的电子的模拟。 我们将研究的钉扎电子晶体，这是一个模拟的三维滑动电荷密度波。 我们还建议研究单排电子中的声音，以试图理解一维系统的物理学。 ***