Spin filter using a semiconductor quantum ring side-coupled to a quantum wire

Abstract

We introduce a new spin filter based on spin-resolved Fano resonances due to spin-split levels in a quantum ring (QR) side-coupled to a quantum wire (QW). Spin-orbit coupling inside the QR, together with external magnetic fields, induces spin splitting, and the Fano resonances due to the spin-split levels result in perfect or considerable suppression of the transport of either spin direction. Using the numerical renormalization group method, we find that the Coulomb interaction in the QR enhances the spin filter operation by widening the separation between dips in conductances for different spins and by allowing perfect blocking for one spin direction and perfect transmission for the other. The spin-filter effect persists as long as the temperature is less than the broadening of QR levels due to the QW-QR coupling. We discuss realistic conditions for the QR-based spin filter and its advantages to other similar devices.

5 pages, 4 figures

References in corpus (14)

• Spintronics: Fundamentals and applications
• Energy spectra of quantum rings
• Quantum Dot as Spin Filter and Spin Memory
• Spin interference effects in ring conductors subject to Rashba coupling
• Persistent current in ballistic mesoscopic rings with Rashba spin-orbit coupling
• Quantum Transport in Nonuniform Magnetic Fields: Aharonov-Bohm Ring as a Spin Switch
• Anti-Kondo resonance in transport through a quantum wire with a side-coupled quantum dot
• T-shaped spin filter with a ring resonator
• Spin Hall Current Driven by Quantum Interferences in Mesoscopic Rashba Rings
• Aharonov-Bohm oscillations of a tunable quantum ring
• Magnetotransport through a strongly interacting quantum dot
• Spin filters with Fano dots
• Spin Filter Effects in Mesoscopic Ring Structures
• Kondo Effect in a Many-Electron Quantum Ring

Cited by in corpus (15)

• Fano resonances in nanoscale structures
• Magnetic Quantum Wire as a Spin Filter: An Exact Study
• Electronic transmission in a model quantum wire with side coupled quasiperiodic chains: Fano resonance and related issues
• Aharonov-Bohm interferometer based on n-p junction in graphene nanoribbons
• Aharonov-Bohm ring with a side-coupled atomic cluster: magneto-transport and the selective switching effect
• Fine structure of the local pseudogap and Fano effect for superconducting electrons near a zigzag graphene edge
• Tuning the Fano Resonance with an Intruder Continuum
• Spin polarization control by electric means: proposal for a spin diode
• Conductance of fractional Luttinger liquids at finite temperatures
• Spin Filtering in a Nonuniform Quantum Wire with Rashba Spin-Orbit Interaction
• Tuning Fano resonances by magnetic forces for electron transport through a quantum wire side-coupled to a quantum ring
• Magnetic forces and localized resonances in electron transfer through quantum rings
• Externally controlled selective spin transfer through a two-terminal bridge setup
• Current-Conserving Aharonov-Bohm Interferometry with Arbitrary Spin Interactions
• Spin-polarized localization in a magnetized chain