时间：6月6日10:00

地点： 理科楼204

主讲人：Bertrand I. Halperin 

主办单位： 物理系

主讲人简介：

　　Prof. Bertrand Halperin is the Hollis Professor of Mathematics and Natural Philosophy at Harvard University. His research interests concern many aspects of the theory of condensed matter systems and statistical physics.

　　A major portion of Halperin's work has concerned properties of two-dimensional electron systems at low temperatures in strong magnetic fields, or "quantum Hall systems".  Much of his current research involves the theory of electron states and transport in small particles of a metal or semiconductor.  Much of this work has been motivated by experiments carried out in various laboratories at Harvard.

　　Prof. B. Halperin is a giant in theoretical physics, especially in theoretical condensed matter physics. He is a member of National Academy of Sciences, also a member of  American Academy of Arts and Sciences.Due to his continuous pioneering contributions to physics, Prof. B. Halperin received numerous very prestigious awards such as Oliver E. Buckley Condensed Matter Prize in 1982, Lars Onsager Prize in 2001, Wolf Prize  ( in Physics category ) in 2002. Most recently, he received  American Physical Society (APS) metal in 2019.

讲座摘要：

　　The subject of “quantum Hall effects” refers to a wide range of peculiar phenomena that occur in two-dimensional electron systems in strong magnetic fields at low temperatures. Perhaps the most spectacular of these phenomena are the fractional quantized Hall states, first seen experimentally in 1982. Understanding these phenomena has required the introduction of radically new theoretical concepts, describing how electron-electron interactions can lead to novel states of matter.

　　Recent experiments on a system with two parallel layers of graphene separated by a thin insulator have revealed a new set of fractional quantized Hall states, in which the Coulomb interaction between electrons in different layers plays a crucial role, along with interactions between electrons in the same layer. The talk will review the phenomenology and theory of fractional quantized Hall effects in single layer systems as well as the new results for Coulomb-coupled double layers.