"U.S.-Czechoslovakia Research on the Theory of Magnetoconductivity of a Two-Dimensional Electron Gas in a Periodic Potential"

这项由印第安纳大学的Allan MacDonald博士和捷克斯洛伐克科学院物理研究所的Pavel Streda博士合作的美国-捷克斯洛伐克合作科学计划的主要目标是研究人工构造的二维电子系统的磁导性和相位相干性。当一个以上的朗道能级在费米能级上形成轨迹网络时，我们将考虑这种情况，以便理解边缘态在较弱磁场下输运性质中的作用。研究人员打算研究在高电流密度下可能出现的非线性效应；在由整数S和整数确定的填充因子处出现能隙的量子情况下，可测量的物理量与整数量子数S有什么关系；以及半经典开闭轨迹图与量子能谱之间的关系。研究人员的努力有望深入了解磁场中的传输特性，并开发一种基于传输矩阵方法的理论。这个凝聚态理论项目通过使美国和东欧的顶尖专家能够将互补的人才结合在一起，并在彼此感兴趣和有能力的领域汇集研究资源，实现了促进科学知识的计划目标。

The primary objective of this US-Czechoslovakia Cooperative Science Program between Dr. Allan MacDonald of Indiana University and Dr. Pavel Streda of the Physics Institute of the Czechoslovakian Academy of Sciences is to study magnetoconductivity of artificially structured two-dimensional electron systems and phase coherence. The case when more than one Landau level forms a trajectory network at the Fermi energy will be considered in order to understand the role of edge states in the transport properties at weaker magnetic fields. The researchers intend to study possible non- linear effects that can appear at high current densities; what measurable physical quantity is connected with the integer quantum number s in the quantum case where energy gaps appear at filling factors determined by integers s and o; and the relationship between the semiclassical picture of open and closed trajectories and the quantum energy spectrum. The researchers' efforts are expected to produce insight into transport properties in a magnetic field and to develop a theory based on the transmission matrix approach. This project in condensed matter theory fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Eastern Europe to combine complementary talents and pool research resources in areas of strong mutual interest and competence.