介观电容器高频量子输运行为的理论研究

项目名称： 介观电容器高频量子输运行为的理论研究

项目编号： No.11504248

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 殷曰

作者单位： 四川大学

项目金额： 20万元

中文摘要： 介观电容器是介观物理中的一种较新的器件，近十年来受到了广泛关注。相比于其他介观量子器件，人们在其中能更好的观测含时输运过程中的单电子量子干涉特性。之前对介观电容器的的研究集中在低频区域内，在本研究中，我们将考察高频区域内介观电容器的线性与非线性响应。对于线性响应，我们将推广之前的延迟电流图像到高频区域，以帮助人们更好的理解和描述介观电容器的高频交流输运行为。对于非线性响应，我们首先利用非平衡格林函数方法，借用人们在半导体非线性光学与自旋电子学中的经验，建立一套描述介观电容器非线性响应的量子动力学理论。然后我们利用该理论考察如下问题：如何利用各种复杂电压信号调控介观电容器，从而实现更细致的单电子量子相干操控？我们期望本研究可以帮助人们加深对于介观系统中电子电荷输运行为的认识。

中文关键词： 交流量子输运；非平衡格林函数

英文摘要： Being a new elementary system in mesoscopic physics, mesoscopic capacitors have attracted much attention in recent years. Comparing to other elementary systems, the quantum effects in the time-dependent single-electron charge transport can be better demonstrated in the mesoscopic capacitor. The study of the time-dependent charge transport in the mesoscopic capacitor can also help people to gain insight into the single-electron charge dynamics on a mesoscopic scale. Previous works on the time-dependent transport of the mesoscopic capacitor mainly focus on the low frequency region. In this study, we will concentrate on the high frequency region. As far as the linear response is concerned, we will generalize the delayed-current picture into the high frequency region. Such picture will help people to have a better understanding of the charge transport properties in the mesoscopic capacitor. As far as the nonlinear response is concerned, following the procedure used in nonlinear optics of semiconductors and spintronics, we will first build up a theory to study the dynamics of the electron charge in mesoscopic capacitors within the framework of non-equilibrium Green functions. Such theory will offer a means to extract charge transport properties (such as electron waiting times, charge decoherence time, etc.) from the nonlinear response of the mesoscopic capacitor. Then, within such theory, we try to answer the question: how to control the single electron transport via varies voltage signal in the mesoscopic capacitor? We expert that our study will be helpful on the further development of mesoscopic time-dependent transport.

英文关键词： AC quantum transport;Non-equilibrium Green function