SCL Seminar by Branislav Nikolic

Prof. Branislav Nikolic from University of Delaware visited SCL and present a seminar:

"What can topological insulators do for spintronics?"


Topological insulators (TIs) are newly discovered class of "Dirac" materials which possess an energy gap in the bulk, akin to conventional band insulators, while hosting metallic edge [in two dimensions (2D)] or surface [in three dimensions (3D)] states. Their the low-energy quasiparticles behave as massless Dirac fermions whose spins are locked to their momenta due to spin-orbit coupling of the Rashba type which is, however, order of magnitude larger than its more familiar counterpart in two-dimensional electron gases within semiconductor heterostructures. The TIs have attracted considerable attention by the basic research communities, because of offering a platform to probe exotic particles borrowed from high energy physics (such as axions, magnetic monopoles and Majorana fermions), as well as by the applied research communities interested in spintronics and quantum computing. In this talk I will discuss possible routes to integrate 2D (such as graphene with heavy adatoms) or 3D (such as BiSe layered compounds) TIs into spintronic heterostructures with ferromagnets (F) that would make it possible to test our theoretical predictions for: (i) quantized spin and charge pumping in 2DTI/F heterostructures; (ii) spin-transfer torque in vertical and lateral 3DTI/F heterostructures; and (iii) spin-Seebeck effect in three-terminal 3DTI/F devices.