Geometry and linearly polarized cavity photon effects on the charge and spin currents of spin-orbit interacting electrons in a quantum ring

Abstract

We calculate the persistent spin current inside a quantum ring as a function of the strength of the Rashba or Dresselhaus spin-orbit interaction. We provide analytical results for the spin current of a one-dimensional (1D) ring of non-interacting electrons for comparison. Furthermore, we calculate the time evolution in the transient regime of a two-dimensional (2D) quantum ring connected to electrically biased semi-infinite leads using a time-convolutionless non-Markovian generalized master equation. In the latter case, the electrons are correlated via the Coulomb interaction and the ring can be embedded in a photon cavity with a single mode of linearly polarized photon field. The electron-electron and electron-photon interactions are described by exact numerical diagonalization. The photon field can be polarized perpendicular or parallel to the charge transport. We find a pronounced charge current dip associated with many-electron level crossings at the Aharonov-Casher phase $\Delta \Phi =\pi$, which can be disguised by linearly polarized light. Qualitative agreement is found for the spin currents of the 1D and 2D ring. Quantatively, however, the spin currents are weaker in the more realistic 2D ring, especially for weak spin-orbit interaction, but can be considerably enhanced with the aid of a linearly polarized electromagnetic field. Specific spin current symmetries relating the Dresselhaus spin-orbit interaction case to the Rashba one are found to hold for the 2D ring in the photon cavity.

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Cited by in corpus (7)

• Spin-dependent heat and thermoelectric currents in a Rashba ring coupled to a photon cavity
• Photon-induced tunability of the thermospin current in a Rashba ring
• Single-photon controlled thermospin transport in a resonant ring-cavity system
• Generalized Master Equation Approach to Time-Dependent Many-Body Transport
• Excitation spectra of a quantum ring embedded in a photon cavity
• Impact of a circularly polarized cavity photon field on the charge and spin flow through an Aharonov-Casher ring
• Lamb Shift of Energy Levels in Quantum Rings