Dynamics of the Wigner Electron Crystal on Liquid Helium Surfaces

液氦表面维格纳电子晶体的动力学

基本信息

批准号：
11440102
负责人：
SHIRAHAMA Keiya
金额：
$ 10.3万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440102/
关键词：
Wigner Crystal Two-Dimensional Electron System Nonlinear Conduction Liquid Helium 非線型伝導

项目摘要

In this research project, we studied the dynamics of the Wigner crystal phase of two-dimensional electrons trapped on free surfaces of liquid helium. In order to elucidate the mechanisms of nonlinear transport phenomena including (1) the conductivity jump, and (2) proportionality of the longitudinal conductivity to the driving voltage, under a perpendicular magnetic field, and (3) the non-Ohmic conduction on a liquid ^3He surface, we have conducted experiments to make a real-time observation of the nonlinear crystal dynamicsWe have developed a new experimental method, using a "t^2" voltage pulse, whose leading and trailing edges change in proportion to the square of time. This pulse gives a continuous sweep of the driving force applied to the crystal. The observed response clearly shows the sliding behavior, revealing that the external force to the crystal determines the sliding transition.In addition to the above experiments, we have studied the electrons on the free surface of ^3He-^4He liquid solutions. It offers us a clue to elucidate the effect of the underlying liquid properties(^3He or ^4He) to the dynamics of the Wigner crystal. We have made a conductivity measurement of the electrons trapped on the liquid mixture surfaces with various ^3He concentrations. However, we have observed anomalous resonance phenomena under a magnetic field. The characteristics of the resonance are similar to the properties of so-called edge magnetoplasmons, in which the plasma oscillation propagates around the perimeter of the electron sheet. Further studies of this unexpected resonance are underway.

在这个研究项目中，我们研究了液氦自由表面上捕获的二维电子维格纳晶相的动力学。为了阐明非线性输运现象的机制，包括（1）电导率跳跃，（2）垂直磁场下纵向电导率与驱动电压的比例，以及（3）液体上的非欧姆传导^3He表面，我们进行了实验，实时观察非线性晶体动力学我们开发了一种新的实验方法，使用“t^2”电压脉冲，其前沿和后沿与时间的平方成比例变化。该脉冲对施加到晶体的驱动力进行连续扫描。观察到的响应清楚地显示了滑动行为，揭示了晶体的外力决定了滑动转变。除了上述实验之外，我们还研究了^3He-^4He液体溶液自由表面上的电子。它为我们提供了阐明潜在液体特性（^3He 或 ^4He）对维格纳晶体动力学影响的线索。我们对不同 ^3He 浓度的液体混合物表面上捕获的电子进行了电导率测量。然而，我们观察到磁场下的反常共振现象。共振的特性类似于所谓的边缘磁等离子激元的特性，其中等离子体振荡围绕电子片的周边传播。对这种意想不到的共振的进一步研究正在进行中。