Condensed Matter Physics Seminar: Interferometry, spin-filtering, and topological effects in 3D topological insulator nano wires

Dr. Roni Ilan, UC Berkeley

22 December 2014, 16:00 
Shenkar Building, Room 204 
Condensed Matter Physics Seminar

Abstract:

A three dimensional topological insulator (3DTI) is a vastly studied symmetry protected topological phase. Its surface state encloses a three dimensional bulk material and forms a two dimensional Dirac metal with no boundary. In this talk I will describe how this is significant in using topological insulator nano wires and films in order to generate, manipulate, and detect topological effects unique to 3DTI in transport. I will discuss our recent theoretical works on interfaces and junctions such as a p-n junction, a superconducting - normal (SN) interface and Josephson Junctions, and argue that these proposed setups can be used to address two outstanding challenges: the detection of spin-momentum locking in TI and the detection of topological superconductivity in transport experiments. In particular, I will argue that a p-n junction in the quantum Hall regime forms a Mach-Zehnder interferometer based on spin-momentum locking, functioning as a spin-FET with the advantage of separating spin polarized currents on output. I will also discuss how the SN junction can be used in order to detect topological superconductivity in one dimension, and show that in the presence of a quantizing field it can be mapped onto a Majorana interferometer.

 

Seminar Organizer: Prof. Shimshon Barad

Tel Aviv University, P.O. Box 39040, Tel Aviv 6997801, Israel
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