Professor Ilya Vekhter from Louisiana State University will give a special seminar on recent progress
in the study of heavy fermion and pnictide superconductors, especially on how to determine
superconducting gap. He is an internationally renowned scientist for his pioneering work on
developing a theory to test anisotropic superconducting gap by magnetic field. The seminar will take
place at 11:00am on December 21 (Tuesday), 2010 in the room 31355, Natural Science Building.
Title: Testing anisotropic superconducting gap by magnetic field.
Speaker: Professor Ilya Vekhter (Louisiana State University)
Abstract: The energy gap in many novel superconductors is highly anisotropic, with either nodes
(zeroes) or deep minima at the Fermi surface. Locating the directions along which the gap is small or
vanishes is a crucial step in identifying the correct underlying pairing interactions. I will review
theoretical and experimental results for various methods of determining the gap shape, and show that
rotation of the applied magnetic field relative to the gap minima produces experimentally observable
oscillations in the specific heat and electronic thermal conductivity. I will provide the comparison of
experiment and theory focusing on heavy fermion and pnictide superconductors, and will discuss both
recent successes and open questions.