Josephson-phase-controlled interplay between correlation effects and electron pairing in a three-terminal nanostructure

Abstract

We study the subgap spectrum of the interacting single-level quantum dot coupled between two superconducting reservoirs, forming the Josephson-type circuit, and additionally hybridized with a metallic normal lead. This system allows for the phase-tunable interplay between the correlation effects and the proximity-induced electron pairing resulting in the singlet-doublet (0-$\pi$) crossover and the phase-dependent Kondo effect. We investigate the spectral function, induced local pairing, Josephson supercurrent, and Andreev conductance in a wide range of system parameters by the numerically exact Numerical Renormalization Group and Quantum Monte Carlo calculations along with perturbative treatments in terms of the Coulomb repulsion and the hybridization term. Our results address especially the correlation effects reflected in dependencies of various quantities on the local Coulomb interaction strength as well as on the coupling to the normal lead. We quantitatively establish the phase-dependent Kondo temperature $\log T_K(\varphi )\propto {\cos }^2(\varphi /2)$ and show that it can be read off from the half-width of the zero-bias enhancement in the Andreev conductance in the doublet phase, which can be experimentally measured by the tunneling spectroscopy.

12 pages, 11 figures; v2: minor text corrections, nearly identical to the published version

References in corpus (17)

• Continuous-time Monte Carlo methods for quantum impurity models
• The numerical renormalization group method for quantum impurity systems
• Supercurrent reversal in quantum dots
• Zero-bias anomaly in a nanowire quantum dot coupled to superconductors
• Energy resolution and discretization artefacts in the numerical renormalization group
• Spectral properties of locally correlated electrons in a BCS superconductor
• Critical Current 0-$\pi$ Transition in Designed Josephson Quantum Dot Junctions
• Josephson current through a single Anderson impurity coupled to BCS leads
• Shiba states and zero-bias anomalies in the hybrid normal-superconductor Anderson model
• Tuning Yu-Shiba-Rusinov States in a Quantum Dot
• Real-time diagrammatic approach to transport through interacting quantum dots with normal and superconducting leads
• Numerical Renormalization Group Approach to a Quantum Dot Coupled to Normal and Superconducting Leads
• Kondo effect in asymmetric Josephson couplings through a quantum dot
• Manipulating the magnetic state of a carbon nanotube Josephson junction using the superconducting phase
• Josephson current through a molecular transistor in a dissipative environment
• Proximity effect on spin-dependent conductance and thermopower of correlated quantum dots
• Renormalization effects in interacting quantum dots coupled to superconducting leads

Cited by in corpus (1)

• Interplay between electron pairing and Dicke effect in triple quantum dots structures