Electronic Transport in Microwave-Driven GaAs/AlGaAs Quantum Structures

这个实验凝聚态物理项目将研究暴露在毫米波波长辐射下的二维电子气体中新发现的(i)辐射诱导的电阻振荡和（ii）零电阻/零电导状态。实验将集中在三个主要的推力上：(1)在小磁场中微波激发引起的直流电子输运的新效应；(2)毫米波下的非线性光学效应及其对直流电子输运的影响；(3)微波泵浦量子结构中电流和通量状态成像的前景。提出的工作将继续探索有趣的物理学，特别是在半经典和量子体制中的当前模式形成，以及微波泵浦电子系统中可能的通量状态。对熟悉半导体物理、微波技术和成像技术的研究生进行教育，为他们在国家研究基础设施和高技术产业就业提供良好的服务。当半导体器件暴露在微波辐射下时，其电输运会表现出消失的电阻，这是PI在上一个资助期间发现的一种新效应。本提案寻求资金以继续这项研究，实验主要集中在三个方面：(1)在小磁场中微波激发引起的电子输运的新效应；(2)毫米波下的非线性光学效应及其对电子输运的影响；(3)微波泵浦量子器件中电流分布成像的前景。了解由微波驱动的半导体器件的基本特性也直接关系到自旋电子学和量子信息科学的新兴问题。对熟悉半导体物理、微波技术和成像技术的研究生进行教育，为他们在国家研究基础设施和高技术产业就业提供良好的服务。

This experimental condensed matter physics project will investigate the newly discovered phenomena of (i) radiation-induced resistance oscillations, and (ii) zero-resistance/zero-conductance states, in a two-dimensional electron gas exposed to millimeter wavelength radiation. The experiments will focus on three major thrusts: (1) Novel effects in dc electronic transport induced by microwave excitation in a small magnetic field; (2) Nonlinear optical effects in the millimeter wave regime and their influence on dc electronic transport; and (3) The prospect for imaging the electrical currents and flux states in a microwave-pumped quantum structure. The proposed work will continue to explore interesting physics, in particular the current pattern formations in the semi-classical and quantum regimes, and possible flux states in a microwave-pumped electronic system. Education of graduate students familiar with semiconductor physics, microwave technology, and imaging technique serves them well for employment in the national research infrastructure and high-technology industry. Electrical transport in a semiconductor device can exhibit vanishing resistance when it is exposed to microwave radiation, a new effect which was discovered by the PI during the previous grant period. This proposal seeks funding to continue this investigation, with experiments focused on three major aspects: (1) Novel effects in electronic transport induced by microwave excitation in a small magnetic field; (2) Nonlinear optical effects in the millimeter wave regime and their influence on electronic transport; and (3) The prospect for imaging the electrical current distribution in a microwave-pumped quantum device. Understanding of fundamental properties of a semiconductor device driven by microwaves is also directly relevant to emerging issues in spintronics and quantum information science. Education of graduate students familiar with semiconductor physics, microwave technology, and imaging technique serves them well for employment in the national research infrastructure and high-technology industry.