Theory of Electrons in Solids

本理论研究的目的是为量子信息处理和计算以及自旋增强光电子学的基础器件的构建做出贡献。该研究计划在半导体纳米结构中利用激光操纵电子及其自旋自由度来实现量子算法的基本物理过程的理论基础上进行。激光束中的光子可以激发半导体纳米点中的电子进入一种称为激子的状态。光的圆偏振也可以给激子一个特定的自旋。在这里，选择自旋极化激子作为量子信息的基本单位量子比特的物理表示。单个激子的光控制处理量子比特，两个相互作用激子的光控制产生量子逻辑器件的操作。研究包括：(1)计算多激子态的能量结构；(2)量子点在强激光激励下的非线性光谱理论，作为操作条件的诊断工具；(3)设计基本器件操作的光学过程；(4)激子量子性质的环境退化（退相干）研究；(5)通过数值模拟验证了设计的时间序列运算，实现了简单版本的关键量子算法。这项理论研究的目的是为量子信息处理和计算以及自旋增强光电子学的基础器件的构建做出贡献。本研究计划在半导体纳米结构中利用激光操纵电子及其自旋自由度来实现量子算法的基本物理过程的理论基础上进行

0099572ShamThe aim of this theoretical research is to contribute to the construction of fundamental devices in quantum information processing and computation, and in spin-enhanced optoelectronics. The research is planned on the theory of the basic physical processes involved in the realization of the quantum algorithms by means of laser manipulation of electrons and their spin degress of freedom in semiconductor nanostructures. A photon in the laser beam can excite an electron in a semiconductor nano-dot into a state known as an exciton. The circular polarization of the light can also give the exciton a specific spin. Here, the spin-polarized exciton is selected as the phsyical representation of the fundamental unit of quantum information, the qubit. Optical control of a single exciton addresses the qubit and optical control of two interacting excitons yields the operation of a quantum logic device. The research consists of (1) a computation of the energy structures of the multiexciton states; (2) a theory of the nonlinear optical spectra of the quantum dot under intense laser excitation as a diagnostic tool for the conditions of operations; (3) design of the optical processes for the operations of the basic devices; (4) a study of the environmental degradation of the quantum nature of the exciton (decoherence); and (5) test of the design by numerical simulations of the time series of operations to accomplish simple versions of key quantum algorithms.%%%The aim of this theoretical research is to contribute to the construction of fundamental devices in quantum information processing and computation, and in spin-enhanced optoelectronics. The research is planned on the theory of the basic physical processes involved in the realization of the quantum algorithms by means of laser manipulation of electrons and their spin degress of freedom in semiconductor nanostructures.***