Quantum phase transition in a double quantum dot Josephson junction driven by electron-electron interactions

Abstract

In this work, we employ a surrogate BCS model with discrete energy levels to investigate a hybrid system comprising two quantum dots (QD1 and QD2), where QD1 is tunnel-coupled to two superconducting leads. Through exact diagonalization of this system, we obtain numerically exact solutions that enable rigorous computation of key physical quantities. Our analysis reveals a rich phase diagram featuring multiple controllable phase transitions mediated by quantum dot interactions. Specifically, the system first undergoes an initial phase transition when tuning QD2's interaction strength while maintaining QD1 in the non-interacting regime. Subsequent adjustment of QD1's interaction induces a secondary phase transition, followed by a third transition arising from inter-dot coupling modulation. Furthermore, we demonstrate that parallel magnetic field application can drive reversible ferromagnetic-antiferromagnetic phase transitions under specific parameter conditions. Finally, we report the emergence of non-local magnetization phenomena when subjecting QD1 to weak magnetic fields. And our results demonstrate that the orientation of nonlocal magnetization can be precisely manipulated through systematic adjustment of the on-site interaction strength $U_2$ in QD2.

12 pages, 9 figures

References in corpus (44)

• Proximity effects in superconductor-ferromagnet heterostructures
• Spin-resolved Andreev levels and parity crossings in hybrid superconductor-semiconductor nanostructures
• Supercurrent reversal in quantum dots
• Josephson ${\phi }_0$-junction in nanowire quantum dots
• Josephson and Andreev transport through quantum dots
• Self-consistent description of Andreev bound states in Josephson quantum dot devices
• Kondo Effect and Josephson Current through a Quantum Dot between Two Superconductors
• 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 nanoscale magnetic quantum dot
• Even-odd effect in Andreev Transport through a Carbon Nanotube Quantum Dot
• Andreev Molecules in Semiconductor Nanowire Double Quantum Dots
• How to discretize a quantum bath for real-time evolution
• The Anderson-Josephson quantum dot -- A theory perspective
• Josephson current in strongly correlated double quantum dots
• Supercurrent in a double quantum dot
• Perturbation theory of a superconducting $0-\pi$ impurity quantum phase transition
• Unconventional Superconductivity in Double Quantum Dots
• Josephson current through interacting double quantum dots with spin-orbit coupling
• Interplay between Josephson effect and magnetic interactions in double quantum dots
• Two-Impurity Yu-Shiba-Rusinov States in Coupled Quantum Dots
• Controllable pi junction in a Josephson quantum-dot device with molecular spin
• Josephson current through a Kondo molecule
• Distributional exact diagonalization formalism for quantum impurity models
• Triplet-blockaded Josephson supercurrent in double quantum dots
• Equilibrium and time-dependent Josephson current in one-dimensional superconducting junctions
• 0-Pi quantum transition in a carbon nanotube Josephson junction: Universal phase dependence and orbital degeneracy
• Generalized atomic limit of a double quantum dot coupled to superconducting leads
• Surrogate model solver for impurity-induced superconducting subgap states
• Magneto-electric spectroscopy of Andreev bound states in Josephson quantum dots
• Anomalous Josephson current through a driven double quantum dot
• Gatemon qubit based on a thin InAs-Al hybrid nanowire
• Josephson junctions in double nanowires bridged by in-situ deposited superconductors
• Direct Transport between Superconducting Subgap States in a Double Quantum Dot
• Non-equilibrium transport through a Josephson quantum dot
• Washing out of the 0-pi transition in Josephson junctions
• Signatures of coherent electronic quasiparticles in the paramagnetic Mott insulator
• Large Tunable Thermophase in Superconductor -- Quantum Dot -- Superconductor Josephson Junctions
• Polaron effects on the dc- and ac-tunneling characteristics of molecular Josephson junctions
• Rigorous Wilsonian Renormalization Group for impurity models with a spectral gap
• Kondo physics of the Anderson impurity model by Distributional Exact Diagonalization
• Field-free Josephson diode effect in interacting chiral quantum dot junctions
• Double-quantum-dot Andreev molecules: Phase diagrams and critical evaluation of effective models
• Phase and Thermal Driven Transport across T-Shaped Double Quantum Dot Josephson Junction