Kinetics of spin relaxation in quantum wires and channels: Boundary spin echo and formation of a persistent spin helix

Journal Article · Sat Oct 15 00:00:00 EDT 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.84.155306· OSTI ID:21596900

Slipko, Valeriy A ^[1]; Pershin, Yuriy V ^[1]

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1. Department of Physics and Astronomy and USC Nanocenter, University of South Carolina, Columbia, South Carolina 29208 (United States)

In this paper we use a spin kinetic equation to study spin-polarization dynamics in one-dimensional (1D) wires and 2D channels. The spin kinetic equation is valid in both diffusive and ballistic spin transport regimes and therefore is more general than the usual spin drift-diffusion equations. In particular, we demonstrate that in infinite 1D wires with Rashba spin-orbit interaction the exponential spin-relaxation decay can be modulated by an oscillating function. In the case of spin relaxation in finite length 1D wires, it is shown that an initially homogeneous spin polarization spontaneously transforms into a persistent spin helix. We find that a propagating spin-polarization profile reflects from a system boundary and returns back to its initial position similarly to the reflectance of sound waves from an obstacle. The Green's function of the spin kinetic equation is derived for both finite and infinite 1D systems. Moreover, we demonstrate explicitly that the spin relaxation in specifically oriented 2D channels with Rashba and Dresselhaus spin-orbit interactions of equal strength occurs similarly to that in 1D wires of finite length. Finally, a simple transformation mapping 1D spin kinetic equation into the Klein-Gordon equation with an imaginary mass is found thus establishing an interesting connection between semiconductor spintronics and relativistic quantum mechanics.

• OSTI ID: 21596900
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 84, Issue 15; Other Information: DOI: 10.1103/PhysRevB.84.155306; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DIFFUSION EQUATIONS
GREEN FUNCTION
KINETIC EQUATIONS
KINETICS
KLEIN-GORDON EQUATION
L-S COUPLING
MASS
ONE-DIMENSIONAL CALCULATIONS
QUANTUM MECHANICS
QUANTUM WIRES
RELATIVISTIC RANGE
RELAXATION
SEMICONDUCTOR MATERIALS
SIMULATION
SPIN
SPIN ECHO
SPIN ORIENTATION
TRANSFORMATIONS
ANGULAR MOMENTUM
COUPLING
DIFFERENTIAL EQUATIONS
ENERGY RANGE
EQUATIONS
FIELD EQUATIONS
FUNCTIONS
INTERMEDIATE COUPLING
MATERIALS
MECHANICS
NANOSTRUCTURES
ORIENTATION
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE PROPERTIES
WAVE EQUATIONS