PHYSICS AND ASTRONOMY COLLOQUIUM

Thursday, November 16, 2006
4:10 pm

1415 Biomedical & Physical Sciences Bldg.
Refreshments at 3:30 pm in Rm. 1400 BPS Bldg.


Speaker: Laura H. Greene
         Department of Physics &
         the Frederick Seitz Materials Research Laboratory
         University of Illinois at Urbana-Champaign
         Urbana, IL 61801
         lhg@uiuc.edu

Title:   High Temperature Superconductors: Playgrounds for Broken Symmetries

Abstract:

Studies of symmetries and the consequences of breaking them have lead to
deeper understanding in many areas of science. The high-temperature super-
conductors, discovered in 1986, motivated an unprecedented world-wide flurry
of research:  not only because applications are promising, but because they
also represent a fascinating new state of matter that breaks certain funda-
mental symmetries.

After providing a general background on broken symmetries and superconduc-
tivity, we show how planar tunneling spectroscopy can detect broken gauge
(superconductivity), reflection (d-wave symmetry superconducting order
parameter) and time-reversal (ferromagnetism) symmetries.