Natan Andrei – Rutgers University
Date/Time/Location
Thursday, October 24th, 2:00 pm; Hill Center 705
Quantum impurity in interacting and non-interacting media
When a local spin impurity is placed in a metal, modeled as a non-interacting gas of electrons, it is screened by a cloud of electrons around it. This is the Kondo effect which I will discuss in detail. What happens when instead the impurity is placed in a superconductor? The traditional answer is that in a 3-dimensional superconductor the impurity is screened by a local bound state. This answer fails in one dimension where quantum fluctuations play an important role and as I shall show, the answer is more interesting - a rich phase diagram emerges. Then I will place the impurity in an open dissipative environment and will find a similar phase diagram. I will discuss the origin of the similarity.