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Spin-current modulation and square-wave transmission through periodically stubbed electron waveguides

X. F. Wang·P. Vasilopoulos·F. M. Peeters
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Abstract

Ballistic spin transport through waveguides, with symmetric or asymmetric double stubs attached to them periodically, is studied systematically in the presence of a weak spin-orbit coupling that makes the electrons precess. By an appropriate choice of the waveguide length and of the stub parameters injected spin-polarized electrons can be blocked completely and the transmission shows a periodic and nearly square-type behavior, with values 1 and 0, with wide gaps when only one mode is allowed to propagate in the waveguide. A similar behavior is possible for a certain range of the stub parameters even when two-modes can propagate in the waveguide and the conductance is doubled. Such a structure is a good candidate for establishing a realistic spin transistor. A further modulation of the spin current can be achieved by inserting defects in a finite-number stub superlattice. Finite-temperature effects on the spin conductance are also considered.

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X. F. Wang, P. Vasilopoulos, F. M. Peeters. 2002-04-18. Spin-current modulation and square-wave transmission through periodically stubbed electron waveguides. https://doi.org/10.1103/physrevb.65.165217

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