Transport and Tunneling Studies of Electronic Materials at Quantum Critical Points

该个人研究者奖将资助一个项目，其目标是了解金属-绝缘体过渡（MIT）附近的一维、二维或三维系统中的电传输性质。人们认为，在这种情况下，这种行为反映了金属与绝缘体分离的零温度量子临界点。在这一点的双方，行为被认为是量子力学基态的反映，但这是理解的程度是最小的。在某种程度上，这是因为用朗道液体来描述金属的传统方法是不充分的，而且金属的性质主要是由库仑相关关系决定的。这位研究者的实验室已经开发出技术，可以使用各种方法在所有维度上持续“调谐”麻省理工学院……磁场调谐，薄膜在低温下的连续生长，电线截面积的调整。传输、电子隧穿和霍尔效应测量将被用于建立跃迁的实验描述和测试理论模型，测量温度可低至20 mK，磁场可高至20 t。研究生将接受凝聚态物理和技术方面的培训。物理问题是当前的，并解决了在降维中电传输的未知方面。材料和加工技术是最先进的，将为他们未来的职业生涯做好准备，有各种各样的选择。这个个人研究者奖将资助那些解决材料电子特性最基本方面的工作……金属绝缘体过渡。这种转变是金属和绝缘体之间差异的顶点。此外，由于我们将研究一维、二维和三维的电输运，它不仅解决了这种转变的维度，我们学到的物理和材料问题将具有实际重要性。随着集成电路和电子存储器上的布线越来越小，它接近这些尺寸极限。研究生将接受凝聚态物理和技术方面的培训。物理问题是当前的，并解决了在降维中电传输的未知方面。材料和加工技术是最先进的，将为他们未来的职业生涯做好准备，有各种各样的选择。

This individual investigator award will fund a project with a goal of understanding the nature of electrical transport in systems of one, two or three dimensions in the vicinity of the metal-insulator transition (MIT). It is believed that in this regime, the behavior reflects a zero temperature quantum critical point that separates the metal from the insulator. On both sides of this point, the behavior is believed to be reflective of quantum mechanical ground states but the extent to which this is understood is minimal. In part this is because the traditional description of a metal in terms of a Landau liquid is simply inadequate and the properties are dominated by coulomb correlations. This investigator's laboratory has developed techniques to continuously "tune" through the MIT in all dimensions using a variety of methods...magnetic field tuning, continuous growth of films at low temperature, and adjustment of cross-sectional area of wires. Transport, electron tunneling and Hall effect measurements down to a temperature of 20 mK and up to magnetic fields of 20T will be used to build an experimental description of the transition and to test theoretical models. Graduate students will receive training both in condensed matter physics and technology. The physics issues are current and address the unknown aspects of electrical transport in reduced dimensions. The technology in materials and processing is state-of-the-art and will prepare them for a future career with a wide variety of options.This individual investigator award will fund work that addresses one of the most fundamental aspects of the electronic properties of materials...the metal insulator transition. This transition is at the apex of the differences between metals and insulators. Furthermore, as we will study the electrical transport in one, two and three dimensions, it not only addresses the dimensionality of this transition, the physics and materials issues that we learn will have practical importance. As wiring on integrated circuits and electronic memory gets smaller, it approaches these dimensionality limits. Graduate students will receive training both in condensed matter physics and technology. The physics issues are current and address the unknown aspects of electrical transport in reduced dimensions. The technology in materials and processing is state-of-the-art and will prepare them for a future career with a wide variety of options.