Journal Club Seminar Series 2009 No.3

Date: 26 March (Thurday) 2009
Time: 4:00am-5:30pm
Venue:Physics Resource Room, S13-02-14

Speaker: Wang Xuesen
Title: Novel boundary states of topological insulators for spintronic applications

Abstract:
It is envisioned in ideal spintronics that information storage, transmission and processing are carried out using pure spin current and spin accumulation, which are controlled with electric field or voltage.  Charge current is avoided in these processes so that they are (almost) dissipationless.  Such dissipationless spin current and accumulation may be realized with quantum spin Hall effect (QSHE) in topological insulators which are some narrow-gap semiconductors.   In these topological insulators, there are robust Kramers pairs of boundary states which are in the bulk bandgap and move in opposite directions for opposite spins.  HgTe quantum well, Bi atomic layers and particularly Bi1-xSbx alloy are among these QSHE materials.  

References:

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[2] X.-L. Qi, T.L. Hughes, S.-C. Zhang, Topological field theory of time-reversal invariant insulators, Phys. Rev. B 78, 195424 (2008).

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[4] J.C.Y. Teo, L. Fu, C.L. Kane, Surface states and topological invariants in three-dimensional topological insulators: Application to Bi1-xSbx, Phys. Rev. B 78, 045426 (2008).

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[6] M.-H. Liu, G. Bihlmayer, S. Blügel, C.-R. Chang, Intrinsic spin-Hall accumulation in honeycomb lattices: Band structure effects, Phys. Rev. B 76, 121301 (2007).

Speaker: Lakhaphat Lin Aigu
Title: Molecular Spin Qubits