Filtering of spin currents based on ballistic ring

Abstract

Quantum interference effects in rings provide suitable means for controlling spin at mesoscopic scales. Here we apply such a control mechanism to the spin-dependent transport in a ballistic quasi one dimensional ring patterned in two dimensional electron gases (2DEGs). The study is essentially based on the {\it natural} spin-orbit (SO) interactions, one arising from the laterally confining electric field {($\beta$ term) and the other due to to the quantum-well potential that confines electrons in the 2DEG (conventional Rashba SO interaction or $\alpha$ term).} We focus on single-channel transport and solve analytically the spin polarization of the current. As an important consequence of the presence of spin splitting, we find the occurrence of spin dependent current oscillations. We analyze %the effects of disorder by discussing the transport in the presence of one non-magnetic obstacle in the ring. We demonstrate that a spin polarized current can be induced when an unpolarized charge current is injected in the ring, by focusing on the central role that the presence of the obstacle plays.

9 pages, 7 figures, PACS numbers: 72.25.-b, 72.20.My, 73.50.Jt, accepted for publication in J. Phys. - Cond. Mat

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Cited by in corpus (7)

• Stability of spintronic devices based on quantum ring networks
• Magnetoconductance properties of rectangular arrays of spintronic quantum rings
• Determination of Rashba and Dresselhaus spin-orbit fields
• Quantum rings with time dependent spin-orbit coupling: Rabi oscillations, spintronic Schrodinger-cat states, and conductance properties
• Logical XOR gate response in a quantum interferometer: A spin dependent transport
• Curvature effect on spin polarization in a three-terminal geometry in presence of Rashba spin-orbit interaction
• Fano resonances and electron spin transport through a two-dimensional spin-orbit-coupled quantum ring