NETA Talks: Shining Light on Topological Insulators

Posted in : Physics

NETA New York branch’s “NETA Talks Series” continued with Dr. Nuh Gedik’s presentation on December 6, 2013. He delivered a talk on his ongoing research on “Topological Insulators.”

NETA Talks Series aims to bring together scientists in New York Metropolitan Area to provide them a platform for sharing their expertise and ideas for networking and for seeking collaboration opportunities.

Date: Friday, December 6, 2013

Venue: Columbia University

Interschool Lab, 750 Schapiro / CEPSR (530 West 120th Street)

Abstract: Topological insulators (TIs) are novel materials that do not conduct electricity in their bulk but possess exceptional conducting
electronic states on their surface. These surface electrons have a number of highly unusual characteristics: (i) they behave like massless
relativistic particles similar to photons (ii) their spin is locked perpendicular to their momentum and (iii) this state is robust against
moderate disorder. Understanding and characterizing unique properties of these materials can lead to novel applications such as current induced
magnetization or extremely robust quantum memory bits. In this talk, I will first give a brief introduction to these materials and then describe our
recent experiments in which we used ultrashort laser pulses to probe and control properties of the topological surface states. Utilizing the short
duration of these pulses, we succeeded in capturing femtosecond movies of the electronic energy bands in a three dimensional manner. These movies reveal an exotic hybrid state between electrons and light which was predicted theoretically but has never been observed in solids before.

Bio: Professor Gedik received his B.S. in Physics in 1998 from Bogazici University, Istanbul, Turkey and his Ph.D in Physics in 2004 from
University of California, Berkeley. After his Ph.D, he moved to Caltech where he worked as a postdoctoral scholar.


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