BYR Achieve · 镜像论坛

【以下文字转载自 BYR_Bulletin 讨论区】发信人: ZhangZhenRen (Andromeda||[路]小卒||20.cn_囧), 信区: BYR_Bulletin 标题: 学术讲座通知发信站: 北邮人论坛 (Mon Sep 28 14:41:07 2009), 站内学术讲座通知应我校副校长、北邮“通信与网络核心技术”学科创新引智基地（简称“111基地”）主任任晓敏教授邀请，我校111基地海外学术骨干——俄罗斯科学院圣彼得堡物理技术研究教育中心副主任Alexander A. Gorbatsevich院士将于10月12日至10月18日到访北邮，开展学术交流与合作研究。访问期间，Gorbatsevich院士将为我校师生作精彩的学术报告。讲座题目：WAVE-FUNCTION ENGINEERING IN NANOSTRUCTURES FOR STUDYING FUNDAMENTAL PHYSICS 主讲人：Alexander A.Gorbatsevich院士主持人：任晓敏教授时间：2009年10月12日（星期一）下午16：00—17：00 地点：办公楼501报告厅讲座内容简介： Methods of band-structure and wave-function engineering proved to be a useful tool for both studying fundamental physics and creating various types of semiconductor devices which form the basis of modern information technologies. A description will be given in the lecture of some recent results in charge carrier scattering theory which can be observed in semiconductor heterostructures created with the help of methods of wave-function engineering. We will start with the short overview of envelop function method for electron sates description in semiconductor heterostructures. Envelop function (or effective mass) method describes inhomogeneous structures including heterostructures in long-wave-length approximation where all the details of microscopic potentials are effectively described by some number of macroscopic parameters in the Hamiltonian in the Boundary Conditions (BC). A novel approach to the derivation of BC for envelop functions will be presented based on the solution of the inverse scattering problem. This approach makes it possible to determine not only the parameters of the generalized BC but the very location of the macroscopic heterostructure boundary within the elementary cell as well. In heterostructures without the inversion center the location of heterostructure boundary as it should be used in the macroscopic envelop function approach can deviate considerably from its true microscopic location. Based on this result “dark matter objects in crystals” are explicitly constructed which are completely invisible in low energy electron scattering. Wave-function engineering methods can be used to control the parameters of different types of resonances in electron scattering. A novel phenomenon (“collapse of resonances”) will be described in the lecture which can be observed in symmetric three-barrier and/or inverted two-barrier resonant tunneling heterostructures. It means that two resonances with unit transparencies merge into one with transparency less the unity under the variation of heterostructure parameters. This transformation is accompanied by asymmetric redistribution of charge carrier density in symmetric heterostructure. Such transformation was described previously in quantum systems with dissipation and is considered to be a realization of quantum phase transition in an open quantum system. 主讲人简介请见附件。此讲座为前沿科技讲座，欢迎全校师生踊跃参加。校学术委员会信息光子学与光通信教育部重点实验室信息光子学与光通信研究院 2009年9月28日

学术讲座通知 (转载)