Subgap features due to quasiparticle tunneling in quantum dots coupled to superconducting leads

Abstract

We present a microscopic theory of transport through quantum dot set-ups coupled to superconducting leads. We derive a master equation for the reduced density matrix to lowest order in the tunneling Hamiltonian and focus on quasiparticle tunneling. For high enough temperatures transport occurs in the subgap region due to thermally excited quasiparticles, which can be used to observe excited states of the system for low bias voltages. On the example of a double quantum dot we show how subgap transport spectroscopy can be done. Moreover, we use the single level quantum dot coupled to a normal and a superconducting lead to give a possible explanation for the subgap features observed in the experiments published in Appl. Phys. Lett. 95, 192103 (2009).

18 pages, 20 figures, revised according to published version

References in corpus (11)

• Supercurrent reversal in quantum dots
• Josephson and Andreev transport through quantum dots
• Hybrid superconductor-semiconductor devices made from self-assembled SiGe nanocrystals on silicon
• Transport Through Andreev Bound States in a Graphene Quantum Dot
• Even-odd effect in Andreev Transport through a Carbon Nanotube Quantum Dot
• Real-time diagrammatic approach to transport through interacting quantum dots with normal and superconducting leads
• Superconductivity-enhanced bias spectroscopy in carbon nanotube quantum dots
• Transport through a double quantum dot system with non-collinearly polarized leads
• Nonequilibrium transport through a spinful quantum dot with superconducting leads
• Andreev reflection versus Coulomb blockade in hybrid semiconductor nanowire devices
• Markovian kinetic equation approach to electron transport through quantum dot coupled to superconducting leads

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• Cavity photons as a probe for charge relaxation resistance and photon emission in a quantum dot coupled to normal and superconducting continua
• Distribution of waiting times between electron cotunnelings
• Subgap resonant quasiparticle transport in normal-superconductor quantum dot devices
• Transient effects in double quantum dot sandwiched laterally between superconducting and metallic leads
• Sub-gap spectroscopy of thermally excited quasiparticles in a Nb contacted carbon nanotube quantum dot
• Subgap dynamics of double quantum dot coupled between superconducting and normal leads
• Thermally induced subgap features in the cotunneling spectroscopy of a carbon nanotube
• Lasing in a coupled hybrid double quantum dot-resonator system
• Second Order Perturbation Theory for a Superconducting Double Quantum Dot
• A particle conserving approach to AC-DC driven interacting quantum dots with superconducting leads
• Nano-mechanics driven by Andreev tunneling
• Zero energy states clustering in an elemental nanowire coupled to a superconductor
• Long-range coupling between superconducting dots induced by periodic driving
• Influence of superconducting leads energy gap on electron transport through double quantum dot by Markovian quantum master equation approach
• Transient triplet blockade in Andreev junction
• Single charge-current in a normal mesoscopic region attached to superconductor leads via a coupled Poisson Non-equilibrium Green Function formalism