Spin polarized transport driven by square voltage pulses in a quantum dot system

Abstract

We calculate current, spin current and tunnel magnetoresistance (TMR) for a quantum dot coupled to ferromagnetic leads in the presence of a square wave of bias voltage. Our results are obtained via time-dependent nonequilibrium Green function. Both parallel and antiparallel lead magnetization alignments are considered. The main findings include a wave of spin accumulation and spin current that can change sign as the time evolves, spikes in the TMR signal and a TMR sign change due to an ultrafast switch from forward to reverse current in the emitter lead.

11 pages, 5 figures

References in corpus (24)

• Spintronics: Fundamentals and applications
• Quantum Computation with Quantum Dots
• Time-dependent transport in interacting and non-interacting mesoscopic systems
• Single-shot read-out of an individual electron spin in a quantum dot
• Coupled quantum dots as quantum gates
• Driven coherent oscillations of a single electron spin in a quantum dot
• Coherent manipulation of electronic states in a double quantum dot
• Time-Dependent Transport through a Mesoscopic Structure
• Time-Dependent Partition-Free Approach in Resonant Tunneling Systems
• Stimulated and spontaneous optical generation of electron spin coherence in charged GaAs quantum dots
• Theory of Transport through Quantum-Dot Spin Valves in the Weak-Coupling Regime
• Optical control of spin coherence in singly charged (In,Ga)As/GaAs quantum dots
• Interaction-driven spin precession in quantum-dot spin valves
• Nonequilibrium spintronic transport through an artificial Kondo impurity: Conductance, magnetoresistance and shot noise
• Tunnel magnetoresistance of quantum dots coupled to ferromagnetic leads in the sequential and cotunneling regimes
• Spin transport through a single self-assembled InAs quantum dot with ferromagnetic leads
• Electric-field control of tunneling magnetoresistance effect in a Ni/InAs/Ni quantum-dot spin valve
• Spin-flip scattering in time-dependent transport through a quantum dot: Enhanced spin-current and inverse tunneling magnetoresistance
• Coherent manipulation of electron spins up to ambient temperatures in Cr${}^{5+}$(S=1/2) doped K${}_3$NbO${}_8$
• Spin-Dependent Ringing and Beats in a Quantum Dot System
• Spin current through a tunnel junction
• Transient Charging and Discharging of Spin-polarized Electrons in a Quantum Dot
• Negative differential conductance and magnetoresistance oscillations due to spin accumulation in ferromagnetic double-island devices
• Spin polarized transport driven by square voltage pulses in a quantum dot system

Cited by in corpus (3)

• Enhanced photon-assisted spin transport in a quantum dot attached to ferromagnetic leads
• Fano-Kondo Spin Filter
• Spin polarized transport driven by square voltage pulses in a quantum dot system