Symmetry of hole spin transport in a two-terminal quantum system

• We study two-terminal hole spin transport in a p-type, light-hole-heavy-hole coupled, quantum-well system under the influence of Rashba spin-orbit interaction. An expression for the spin polarization of the outgoing hole flux is derived. It is shown that the in-plane spin polarization vanishes identically whenever the outgoing lead supports only heavy-hole channels. This result is independent of the details of the system. By analyzing the symmetries of the system, constraints on the spin-dependent transmission amplitudes are derived. It is shown that under time-reversal symmetry, the total hole spin polarization vanishes whenever the outgoing lead supports only one spin-degenerate hole channel, which is also independent of the details of the system. It is further shown that generally it is difficult to achieve spin polarized currents from a laterally defined Rashba hole device without breaking its transverse reflection symmetry.

Subject headings

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

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art (subject category)

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