University of Minnesota
School of Physics & Astronomy

Abigail and John Van Vleck Lectures

Sir Anthony J. Leggett


John D. and Catherine T. MacArthur Chair and Center for Advanced Study Professor of Physics
University of Illinois at Urbana-Champaign
2003 Nobel Laureate

Public Lecture:
4:00 p.m., Wednesday, April 19, 2006
Tate Laboratory of Physics, Room 150, Van Vleck Auditorium
Does the Everyday World Really Obey Quantum Mechanics?
Reception following lecture in Physics 216
Abstract: Quantum mechanics has been enormously successful in describing nature at the atomic level, and most physicists believe that it is in principle the "whole truth" about the world even at the everyday level. However, such a view prima facie leads to a severe problem. In certain circumstances, the most natural interpretation of the theory implies that no definite outcome of an experiment occurs until the act of "observation." For many decades this problem was regarded as "merely philosophical," in the sense that it was thought that it had no consequences which could be tested in experiment. However, in the last dozen or so years the situation has changed very dramatically in this respect. Leggett will discuss the problem, some popular "resolutions" of it, the current experimental situation and prospects for the future.
Colloquium:
4:00 p.m., Thursday, April 20, 2006
Tate Laboratory of Physics, Room 150
BCuprate Superconductivity Without a Model
Refreshments served in room 216 at 3:30 p.m.
Abstract: What can we reasonably say we know for sure about superconductivity in the cuprates, without reliance on any microscopic model? On the basis of this knowledge and of some very generic and hopefully reasonable assumptions, are there interesting questions we can ask which we have some hope of answering definitively by experiment? Identified is one such question, namely: In which regions of momentum and frequency space is the inter-conduction electron Coulomb interaction energy saved (or expended) when the system becomes superconducting? A possible answer to this question is conjectured and shown to be consistent with the dependence of the transition temperature on the c-axis layering structure. This answer makes quantitative and experimentally testable predictions.