Ballistic spin-dependent transport of Rashba rings with multi-leads

Journal Article · Sun May 15 00:00:00 EDT 2011 · Annals of Physics (New York)

DOI:https://doi.org/10.1016/j.aop.2010.10.003· OSTI ID:21579887

Guangyao, Huang ^[1]

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1. State Key Laboratory of Optoelectronic Material and Technology and School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

Research Highlights: > Transmission coefficients of each outgoing lead in multi-lead mesoscopic Rashba rings. > Spin polarizations of each outgoing lead in multi-lead mesoscopic Rashba rings. > Resonant and antiresonant conditions of spin polarization in multi-lead Rashba rings. > Symmetries of conductance and spin polarization of symmetric multi-lead Rashba rings. - Abstract: Using the Landauer-Buettiker formula with the transfer matrix technique, we develop a formalism of the ballistic spin-dependent electron transport in the multi-lead Rashba rings. We give analytic formulas of the total conductance G{sub j}, spin-{sigma} conductance g{sub j}{sup {sigma}} and spin polarization P{sub j} of each outgoing lead j, and their resonant and antiresonant conditions. Analytic studying with numerical investigating Rashba rings with several symmetric and asymmetric leads, we find that G{sub j}, g{sub j}{sup {sigma}} and P{sub j} oscillate with the incoming electron energy and the spin-orbit interaction (SOI) strength, and their antiresonances depend on the incoming electron energy, the SOI strength and the outgoing-lead angle with the incoming lead. For the symmetric-lead rings, G{sub j}, g{sub j}{sup {sigma}} and P{sub j} have some symmetries, G{sub j}=G{sub N-j},g{sub j}{sup {sigma}}=g{sub N-j}{sup -{sigma}}, and P{sub j} = -P{sub N-j} for symmetric leads, j and N - j, where the angles between the symmetric outgoing leads j and N - j and the incoming lead are {gamma}{sub N-j} = 2{pi} - {gamma}{sub j}. The spin polarization of the outgoing lead with {gamma}{sub j} = {pi} is exactly zero for even-N-symmetric-lead rings. These symmetries originate from the lead symmetry and time reversal invariance. For asymmetry-lead rings these symmetries vanish.

• OSTI ID: 21579887
• Journal Information: Annals of Physics (New York), Vol. 326, Issue 5; Other Information: DOI: 10.1016/j.aop.2010.10.003; PII: S0003-4916(10)00180-6; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0003-4916
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
ELECTRONS
LEAD
L-S COUPLING
MATRICES
RINGS
SPIN
SPIN ORIENTATION
SYMMETRY
T INVARIANCE
TRANSMISSION
ANGULAR MOMENTUM
COUPLING
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
INTERMEDIATE COUPLING
INVARIANCE PRINCIPLES
LEPTONS
METALS
ORIENTATION
PARTICLE PROPERTIES