Theory of spin blockade, charge ratchet effect, and thermoelectrical behavior in serially coupled quantum-dot system

Abstract

The charge transport of a serially coupled quantum dots (SCQD) connected to the metallic electrodes is theoretically investigated in the Coulomb blockade regime. A closed-form expression for the tunneling current of SCQD in the {\color{red} weak interdot hopping} limit is obtained by solving an extended two-site Hubbard model via the Green's function method. We use this expression to investigate spin current rectification, negative differential conductance, and coherent tunneling in the nonlinear response regime. The current rectification arising from the space symmetry breaking of SCQD is suppressed by increasing temperature. The calculation of SCQD is extended to the case of multiple parallel SCQDs for studying the charge ratchet effect and SCQD with multiple levels. In the linear response regime, the functionalities of spin filter and low-temperature current filter are demonstrated to coexist in this system. It is further demonstrated that two-electron spin singlet and triplet states can be readily resolved from the measurement of Seebeck coefficient rather than that of electrical conductance.

11 pages, 9 figures. Revised argument, results unchanged, added references

References in corpus (13)

• Optimal energy quanta to current conversion
• Optimal thermoelectric figure of merit of a molecular junction
• Thermoelectric and thermal rectification properties of quantum dot junctions
• A Generic Model for Current Collapse in Spin Blockaded Transport
• Pauli spin blockade in weakly coupled quantum dots
• Quantum dot spin qubits in Silicon: Multivalley physics
• Shot noise in transport through "double quantum dots"
• Hubbard model description of silicon spin qubits: charge stability diagram and tunnel coupling in Si double quantum dots
• Double quantum dot as detector of spin bias
• Tunneling current spectroscopy of a nanostructure junction involving multiple energy levels
• Transport through a double quantum dot system with non-collinearly polarized leads
• Negative tunnel magnetoresistance and differential conductance in transport through double quantum dots
• Nonthermal broadening in the conductance of double quantum dot structures

Cited by in corpus (12)

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• Long distance coherent tunneling effect on the charge and heat currents in serially coupled triple quantum dots
• Charge and Spin Thermoelectric Transport in Benzene-Based Molecular Nano-Junctions: A Quantum Many-Body Study
• Quantum interference and electron correlation in charge transport through triangular quantum dot molecules
• Effects of metallic electrodes on the thermoelectric properties of zigzag graphene nanoribbons with periodic vacancies
• Superlattice nanowire heat engines with direction-dependent power output and heat current
• Room-Temperature Pauli Spin Blockade and Current Rectification in 15-13-15 Armchair Graphene Nanoribbon Heterostructures
• Tunneling Current Spectra of a Metal Core/Semiconductor Shell Quantum Dot Molecule
• Topological Interface States and Nonlinear Thermoelectric Performance in Armchair Graphene Nanoribbon Heterostructures
• Current Rectification and Seebeck Coefficient of Serially Coupled Double Quantum Dots