【大学频道】北京大学量子材料科学中心呈献 | Dan Shahar of The Weizmann Institute

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图 | Dan Shahar

题目：Disordered superconductors near T=0

报告人：Dan Shahar

单位：The Weizmann Institute

时间：2019-11-13

地点：北京大学

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报告摘要

It turns out that, surprisingly, superconductors have not been studied extensively near T=0. This is mainly because the experimentally accessible and technologically interesting range is usually closer to Tc. With disorder superconductors one obtains the advantage that measurements can be performed down to the mK range. But there, the weak coupling of the Cooper-pair condensate to the thermal phonon system impose severe limitations on reaching equilibrium conditions. There are two different but related manifestations of this that we will discuss. The first is the ubiquitous observation that thin-film superconductors exhibit distinct saturation of the resistance as T approaches zero. We had shown that it can be a result of extrenous electrical noise impinging on the sample.the second is related to the critical current that we measure at low temperatures. We demonstrate that the critical current is a result of nonequilibrium, bi-stable condition that the electronic system develops. Using this approach we are able to predict the critical current in our films to within 1%.

个人简介

Prof. Dan Shahar received his Ph.D. in 1995 from Princeton University; he was a Postdoctoral Research Assistant at Princeton University during 2012–2014; He has been a Professor of Physics at The Weizmann Institute since 2015.