Shot noise and tunnel magnetoresistance in multilevel quantum dots: Effects of cotunneling

Abstract

Spin-dependent transport through a multilevel quantum dot weakly coupled to ferromagnetic leads is analyzed theoretically by means of the real-time diagrammatic technique. Both the sequential and cotunneling processes are taken into account, which makes the results on tunnel magnetoresistance (TMR) and shot noise applicable in the whole range of relevant bias and gate voltages. Suppression of the TMR due to inelastic cotunneling and super-Poissonian shot noise have been found in some of the Coulomb blockade regions. Furthermore, in the Coulomb blockade regime there is an additional contribution to the noise due to bunching of cotunneling processes involving the spin-majority electrons. On the other hand, in the sequential tunneling regime TMR oscillates with the bias voltage, while the current noise is generally sub-Poissonian.

References in corpus (31)

• Spintronics: Fundamentals and applications
• Shot Noise in Mesoscopic Conductors
• Electric Field Control of Spin Transport
• Mesoscopic quantum transport: Resonant tunneling in the presence of strong Coulomb interaction
• Resonant tunneling through ultrasmall quantum dots: zero-bias anomalies, magnetic field dependence, and boson-assisted transport
• Kondo effect in quantum dots coupled to ferromagnetic leads
• Theory of Transport through Quantum-Dot Spin Valves in the Weak-Coupling Regime
• Positive cross-correlations in a three-terminal quantum dot with ferromagnetic contacts
• Full counting statistics of super-Poissonian shot noise in multi-level quantum dots
• Kondo effect in a quantum dot coupled to ferromagnetic leads: A numerical renormalization group analysis
• Noise of a Quantum-Dot System in the Cotunneling Regime
• Tunnel magnetoresistance of quantum dots coupled to ferromagnetic leads in the sequential and cotunneling regimes
• Co-tunneling current and shot noise in quantum dots
• Shot Noise Detection on a Carbon Nanotube Quantum Dot
• The Kondo Effect in the Presence of Magnetic Impurities
• Positive cross-correlations due to Dynamical Channel-Blockade in a three-terminal quantum dot
• Counting statistics and super-Poissonian noise in a quantum dot
• Shot noise in tunneling transport through molecules and quantum dots
• Spin injection in a single metallic nanoparticle: a step towards nanospintronics
• Spin transport through a single self-assembled InAs quantum dot with ferromagnetic leads
• Using single quantum states as spin filters to study spin polarization in ferromagnets
• Kondo effect in a semiconductor quantum dot coupled to ferromagnetic electrodes
• Electric-field control of tunneling magnetoresistance effect in a Ni/InAs/Ni quantum-dot spin valve
• Frequency-Dependent Current Noise through Quantum-Dot Spin Valves
• Zero-bias anomaly in cotunneling transport through quantum-dot spin valves
• Noise Correlations in a Coulomb Blockaded Quantum Dot
• Spin-dependent tunneling and Coulomb blockade in ferromagnetic nanoparticles
• Magnetoresistance of a quantum dot with spin-active interfaces
• Effect of Quantum Confinement on Electron Tunneling through a Quantum Dot
• Transport through two-level quantum dots weakly coupled to ferromagnetic leads
• Cotunneling through two-level quantum dots weakly coupled to ferromagnetic leads

Cited by in corpus (9)

• Spin effects in single electron tunneling
• Effects of different geometries on the conductance, shot noise and tunnel magnetoresistance of double quantum dots
• Probing the exchange field of a quantum-dot spin valve by a superconducting lead
• Transport through single-wall metallic carbon nanotubes in the cotunneling regime
• Influence of spin waves on transport through a quantum-dot spin valve
• Iterative path-integral summations for the tunneling magnetoresistance in interacting quantum-dot spin valves
• The tunnel magnetoresistance in chains of quantum dots weakly coupled to external leads
• Shot noise in a quantum dot coupled to non-magnetic leads: Effects of Coulomb interaction
• Noise and fluctuation relations of a spin diode