Institute of Theoretical Physics
Chinese Academy of Sciences

Colloquium

Title
题目

Superconductivity as a Universal Emergent Phenomenon in Diverse Physical Systems

Speaker
报告人

Prof. Mike Guidry

Department of Physics and Astronomy, University of Tennessee, Knoxville TN, USA　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　Physics Division, Oak Ridge National Laboratory, Oak Ridge TN, USA　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge TN, USA

Date
日期

2013-04-23 PM 15:30 Tuesday

Venue
地点

ITP New Building 6620, 理论物理研究所新楼六层报告厅

Abstract
摘要

Superconductivity having generically recognizable features is observed or suspected across a strikingly broad range of physical systems: for example, in traditional BCS superconductors, cuprate high-temperature superconductors, iron-based high-temperature superconductors, organic superconductors, and heavy-fermion superconductors in condensed matter, in many aspects of low-energy nuclear structure physics, and in various exotic possibilities for gravitationally condensed objects such as neutron stars. Microscopically these are fundamentally different systems, but we note two universal features of their observed superconductivity: (1) It results from a condensate of fermion Cooper pairs, and (2) It is an emergent collective behavior and thus likely has only an abstract dependence on the underlying microscopic physics. Hence, a unified understanding of superconductivity across these highly disparate fields may be possible if it is viewed as resulting from physics that depends only on broad physical principles operating at the emergent scale, with physics at the underlying microscopic scale entering only parametrically. In this talk I will propose that all superconductivity results from the systematic occurrence of generic algebraic structures for the emergent effective Hamiltonian, largely independent of underlying microscopic structure in possibly very diverse systems. Physically, these algebraic structures represent powerful dynamical constraints on how microscopic fermionic building blocks can cohere into collective superconducting behavior, leading to characteristics at the emergent level that are highly universal. This permits transcending the often radical differences in the underlying microscopic Hamiltonians of these varied systems by systematically absorbing their influence on superconductivity into the values of a few effective parameters.