AC spin source

Two-dimensional (2D) topological insulators (Tis) are nothing but the quantum spin Hall phase. This phase is a time-reversal symmetric version of the quantum Hall effect. Each edge hosts two counter propagating modes with opposite spin. During my stay in the Université de Genève in Prof. Markus Büttiker's group we studied this system with the analytical model derived by Bernevig, Hughes and Zhang (BHZ) under a perpendicular magnetic field. We came along with a proposal for a spintronic device that can work either as an AC charge source or, most interestingly, an AC spin source, with no net charge current. This device could work under no magnetic field once quantum point contacts in 2D TIs become experimentally feasible. In the meanwhile, we also propose how this problem can be overcome by working in the quantum Hall regime under a perpendicular magnetic field.

For more details see

Proposal for an ac spin current source. P.P. Hofer, H. Aramberri, C. Schenke, P.A.L. Delplace, Europhys. Lett. 107 (2), 27003 (2014).

Preprint available in arXiv, 1403.6674.