Hidden symmetry in interacting-quantum-dot-based multi-terminal Josephson junctions

Abstract

We study a multi-terminal Josephson junction based on an interacting quantum dot coupled to $n$ superconducting BCS leads. Using an Anderson type model of a local level with an arbitrary onsite Coulomb repulsion, we uncover its surprising equivalence with an effective two-terminal junction with symmetric couplings to appropriately phase-biased leads. Regardless of the strength of the Coulomb interaction, this hidden symmetry enables us to apply well-established numerical and theoretical tools for exact evaluation of various physical quantities, and imposes strict relations among them. Focusing on three-terminal devices, we then demonstrate several phenomena such as the existence of the finite energy band crossings, superconducting transistor and diode effects, as well as current phase relation modulation.

6 pages, 3 figures and Supplementary Material with 8 pages and 5 figures

References in corpus (6)

• Spectral properties of locally correlated electrons in a BCS superconductor
• Josephson current through a single Anderson impurity coupled to BCS leads
• Single fermion manipulation via superconducting phase differences in multiterminal Josephson junctions
• Production of non-local quartets and phase-sensitive entanglement in a superconducting beam splitter
• Josephson effect in multiterminal topological junctions
• Tunable reentrant Kondo effect in quantum dots coupled to metal-superconducting hybrid reservoirs

Cited by in corpus (9)

• Quantum circuits with multiterminal Josephson-Andreev junctions
• Theory of universal diode effect in three-terminal Josephson junctions
• Field-free Josephson diode effect in interacting chiral quantum dot junctions
• Double-quantum-dot Andreev molecules: Phase diagrams and critical evaluation of effective models
• Cooper quartets in interacting hybrid superconducting systems
• Floquet-engineered diode performance in a Majorana-quantum dot Josephson junction
• Andreev bound state spectroscopy of a quantum-dot-based Aharonov-Bohm interferometer with superconducting terminals
• Superconducting Diode Effect in Double Quantum Dot Device
• Scalable Effective Models for Superconducting Nanostructures: Applications to Double, Triple, and Quadruple Quantum Dots