Shot Noise of Spin-Decohering Transport in Spin-Orbit Coupled Nanostructures

Abstract

We generalize the scattering theory of quantum shot noise to include the full spin-density matrix of electrons injected from a spin-filtering or ferromagnetic electrode into a quantum-coherent nanostructure governed by various spin-dependent interactions. This formalism yields the spin-resolved shot noise power for different experimental measurement setups--with ferromagnetic source and ferromagnetic or normal drain electrodes--whose evaluation for the diffusive multichannel quantum wires with the Rashba (SO) spin-orbit coupling shows how spin decoherence and dephasing lead to substantial enhancement of charge current fluctuations (characterized by Fano factors $>1/3$). However, these processes and the corresponding shot noise increase are suppressed in narrow wires, so that charge transport experiments measuring the Fano factor $F_{\uparrow \to \uparrow \downarrow }$ in a ferromagnet/SO-coupled-wire/paramagnet setup also quantify the degree of phase-coherence of transported spin--we predict a one-to-one correspondence between the magnitude of the spin polarization vector and $F_{\uparrow \to \uparrow \downarrow }$.

8 pages, 3 figure; enhanced with 2 new figures

References in corpus (6)

• Suppression of Spin Relaxation in Submicron InGaAs Wires
• Decoherence of transported spin in multichannel spin-orbit coupled spintronic devices: Scattering approach to spin density matrix from the ballistic to the localized regime
• Quantum-to-classical correspondence in open chaotic systems
• Shot noise in a diffusive F-N-F spin valve
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Cited by in corpus (3)

• What can we learn about the dynamics of transported spins by measuring shot noise in spin-orbit-coupled nanostructures?
• Shot Noise Probing of Magnetic Ordering in Zigzag Graphene Nanoribbons
• Spin and Charge Shot Noise in Mesoscopic Spin Hall Systems