Thin Films, Heterostructures and Mesoscale Physics of Quasi-One-Dimensional Conductors

本实验项目主要研究新型电荷密度波（CDW）导体（包括Rb0.3MoO3）薄膜的界面特性。这类材料是迄今为止发现的最显著的导电材料之一，具有许多新颖和潜在有用的特性。部分工作将建立在代尔夫特理工大学van der Zant等人最近的演示之上，该演示表明CDW导体的薄膜可以被制备、定型和表征，这确实证明了新的和潜在有用的CDW现象。与这个小组和康奈尔大学的Buhrman小组合作，将探索这些材料的脉冲激光沉积。图像化和连接单个晶粒的方法，以及用其他材料制备异质结构的方法将被研究。这些薄膜使各种各样的实验成为可能，以探索CDW物理的中尺度方面，并计划了几个这样的实验。此外，基于亚稳CDW状态的存储器件将被制造和表征。介观结构将用于研究CDW相滑移和涡旋动力学。类似mosfet的异质结构将允许调制CDW波矢量、间隙和集体电导。这种装置可用作检测器和混合器。cdw超导体异质结构将用于探索由于这两个基态中竞争配对相互作用而产生的邻近效应。还将进行中尺度cdw -绝缘体- cdw和正常金属-绝缘体- cdw异质结构性质预测的初步试验。这个研究项目是跨学科的，将涉及研究生和本科生，他们将在工业、政府和学术界接受良好的职业培训。这个实验项目是基于“电荷密度波”导体的新型和潜在有用的电子导电膜。在这些材料中，它们通常是非常各向异性的，它们的形状通常是针状的，导电的方式与铜和铝等普通金属完全不同。在这些导体中，带电荷“畴”的协同运动提供导电，具有许多新颖和潜在有用的特性。在这个项目中，将制造和研究这种材料的薄膜，适合纳入电子设备配置，如高频通信设备中使用的“混频器”。这种薄膜的异质结在某些情况下将类似于硅器件技术中众所周知的“MOSFET”结构，并将探索其新特性。这项工作将使人们更好地理解传统金属和绝缘体以及新型电荷密度波导体之间的界面的电学行为，并可能导致电子领域的新应用。这个研究项目是跨学科的，将涉及本科生和研究生，他们将在工业、政府和学术界获得出色的培训。＊＊＊

w:\awards\awards96\num.doc Thorne 9705433 This experimental project focuses on the properties of interfaces involving thin films of novel charge-density wave (CDW) conductors, including Rb0.3MoO3. Materials of this class are among the most remarkable conducting materials ever discovered, and have many novel and potentially useful properties. In part the work will build upon the recent demonstration by van der Zant et al at the Delft University of Technology, that thin films of CDW conductors can be prepared, patterned and characterized, which indeed demonstrate the novel and potentially useful CDW phenomena. Collaboration with this group and the Buhrman group at Cornell will explore pulsed laser depostion of these materials. Methods for patterning and for attaching contacts to indvidual grains, and for preparing heterostructures with other materials will be investigated. These films make possible a broad variety of experiments to probe mesoscale aspects of CDW physics, and several such experiments are planned. In addition, memory devices based on metastable CDW states will be fabricated and characterized. Mesoscopic structures will be used to study CDW phase slip and vortex dynamics. MOSFET-like heterostructures will allow modulation of the CDW wavevector, gap and collective conductance. Such devices may be useful as detectors and mixers. CDW-superconductor heterostructures will be used to explore proximity effects due to the competing pairing interactions in these two ground states. Preliminary efforts to test predictions for the properties of mesoscale CDW-insulator-CDW and normal metal-insulator-CDW heterostructures will also be undertaken. This research project is interdisciplinary in nature and will involve graduate and undergraduate students who will be excellently trained for careers in industry, government and a cademia. %%% This experimental project is based on novel and potentially useful electronic conducting films of "charge-density-wave" conductors. In these materials, which are typically very anisotropic, often needle-like in their shape, electrical conduction occurs in a completely different way than in common metals such as copper and aluminum. In these conductors a cooperative motion of charge-carrying "domains" provides conduction, with many novel and potentially useful properties. In this project, thin films of such materials, suitable for incorporation into electronic device configurations, such as "mixers" of use in high frequency communication equipment, will be fabricated and studied. Heterojunctions of such films will resemble in some cases the "MOSFET" structures well known in the silicon device technology, and will be explored for their novel properties. This work will lead to a much better understanding of the electrical behavior of interfaces between conventional metals and insulators and the novel charge-density-wave conductors, and will possibly lead to new applications in electronics. This research project is interdisciplinary in nature and will involve undergraduate and graduate students who will be excellently trained for positions in industry, government and academia. ***