Department of Physics, Bar Ilan University, Israel

报告摘要：

The superconductor-insulator transition (SIT) is a prototype of a quantum phase transition which is very versatile experimentally: varying a non-thermal tuning parameter such as disorder, thickness, composition, magnetic field or gate-voltage causes the system to switch from a superconductor to an insulator at zero temperature.

Unlike their classic counterparts, quantum phase transitions are governed by quantum fluctuations rather than thermal fluctuations. The direct experimental study of such fluctuations close to the SIT is rather challenging. So far research has mainly concentrated on dc resistivity based measurements such as transport and magnetoresistance and on global and local tunneling spectroscopy. These provide only limited information on the critical behavior through the transition.

In my talk I will describe thermal (specific heat and Nernst effect) experiments designed to measure direct signatures of quantum fluctuations and critical behavior close to the SIT. I will discuss the significance of the results and their contribution to understanding the electronic processes in the vicinity of the quantum phase transition.

报告人简介：

Aviad Frydman is a professor of physics and the head of the nano-electronic laboratory in Bar Ilan University, Israel. He completed his Ph.D. degree in the Hebrew University of Jerusalem and was a postdoctoral researcher in University of California, San Diego Since 1999 he has been a faculty member of Bar Ilan university and spent two visiting-professor years in Yale University and Neel Institute of Grenoble. His research interests include experimental study of the electronic properties of low dimensional systems, nano dots, 1D wires, ultrathin films and granular arrays, focusing on ferromagnets and superconductors.

联系人： 朱北沂/ 8264-9927