Andreev Bound States and Their Signatures

Abstract

Many of the properties of superconductors related to quantum coherence are revealed when the superconducting state is forced to vary in space - in response to an external magnetic field, a proximity contact, an interface to a ferromagnet, or to impurities embedded in the superconductor. Among the earliest examples is Andreev reflection of an electron into a retro-reflected hole at a normal-superconducting interface. In regions of strong inhomogeneity multiple Andreev reflection leads to the formation of sub-gap states, Andreev bound states, with excitation energies below the superconducting gap. These states play a central role in our understanding of inhomogeneous superconductors. The discoveries of unconventional superconductivity in many classes of materials, advances in fabrication of superconducting/ferromagnetic hybrids and nano-structures for confining superfluid ${}^3$He, combined with theoretical developments in topological quantum matter have dramatically expanded the significance of branch conversion scattering and Andreev bound state formation. This collection of articles highlights developments in inhomogeneous superconductivity, unconventional superconductivity and topological phases of superfluid ${}^3$He, in which Andreev scattering and bound states underpin much of the physics of these systems. This article provides an introduction to the basic physics of Andreev scattering, bound-state formation and their signatures. The goal is both an introduction for interested readers who are not already experts in the field, as well as to highlight several examples in which branch conversion scattering and Andreev bound states provide unique signatures in the transport properties of inhomogeneous, topological and unconventional superconductors.

Introduction to a Theme Issue of Philosophical Transactions of the Royal Society on "Andreev Bound States". 21 pages, 8 figures

References in corpus (8)

• The Josephson heat interferometer
• Surface States, Edge Currents and the Angular Momentum of Chiral p-wave Superfluids
• Phase Modulated Thermal Conductance of Josephson Weak Links
• Theory of Nonequilibrium Spin Transport and Spin Transfer Torque in Superconducting-Ferromagnetic Nanostructures
• Heat transport through a Josephson junction
• Quantitative measurements of the thermal resistance of Andreev interferometers
• Multifaceted properties of Andreev bound states: Interplay of symmetry and topology
• Dynamics of spin transport in voltage-biased Josephson junctions

Cited by in corpus (69)

• From Andreev to Majorana bound states in hybrid superconductor-semiconductor nanowires
• Nontopological zero-bias peaks in full-shell nanowires induced by flux tunable Andreev states
• Theory of Majorana zero modes in unconventional superconductors
• Local and non-local quantum transport due to Andreev bound states in finite Rashba nanowires with superconducting and normal sections
• Superconducting phenomena in systems with unconventional magnets
• Enhancing the Josephson diode effect with Majorana bound states
• Spectroscopy of spin-split Andreev levels in a quantum dot with superconducting leads
• Josephson effect and odd-frequency pairing in superconducting junctions with unconventional magnets
• Photon-assisted tunneling at the atomic scale: Probing resonant Andreev reflections from Yu-Shiba-Rusinov states
• Electrical and Thermal Transport in Antiferromagnet-Superconductor Junctions
• Phase-tunable thermal rectification in the topological SQUIPT
• Planar Josephson junctions in germanium: Effect of cubic spin-orbit interaction
• Harnessing Ultraconfined Graphene Plasmons to Probe the Electrodynamics of Superconductors
• Non-Hermitian phase-biased Josephson junctions
• Detecting Majorana Zero Modes via Strong Field Dynamics
• Orientation-dependent transport in junctions formed by $d$-wave altermagnets and $d$-wave superconductors
• Evidence of Andreev blockade in a double quantum dot coupled to a superconductor
• Theory of Disordered Superconductors with Applications to Nonlinear Current Response
• Fundamental dissipation due to bound fermions in the zero-temperature limit
• Probing Fermi sea topology by Andreev state transport
• Thermal signature of Majorana fermions in Josephson junction
• Odd-Parity Quasiparticle Interference in the Superconductive Surface State of UTe2
• Magnetically-Confined Bound States in Rashba Systems
• Josephson diode effect with Andreev and Majorana bound states
• Dissipationless Nonlinearity in Quantum Material Josephson Diodes
• Superconductivity-enhanced spin pumping: Role of Andreev resonances
• Spontaneous symmetry-breaking at surfaces of $d$-wave superconductors: influence of geometry and surface ruggedness
• Transient dynamics of a magnetic impurity coupled to superconducting electrodes: exact numerics versus perturbation theory
• Probing electron-hole weights of an Andreev bound state by transient currents
• Direct and inverse superspin Hall effect in two-dimensional systems: Electrical detection of spin supercurrents
• Weyl Fermions and Broken Symmetry Phases of Laterally Confined ${}^3$He Films
• The Josephson junction as a quantum engine
• Controllable Andreev Bound States in Bilayer Graphene Josephson Junction from Short to Long Junction Limits
• Diamagnetic property and optical absorption in conventional superconductors with magnetic impurities
• Quantum and thermal fluctuations in the dynamics of a resistively and capacitively shunted Josephson junction
• Anomalous Josephson effect of s-wave pairing states in chiral double layers
• Kramers Fulde-Ferrell state and superconducting spin diode effect
• Opportunities for the direct manipulation of a phase-driven Andreev spin qubit
• Subgap states in semiconductor-superconductor devices for quantum technologies: Andreev qubits and minimal Majorana chains
• Tunneling conductance in superconducting junctions with $p$-wave unconventional magnets breaking time-reversal symmetry
• Missing odd-order Shapiro steps do not uniquely indicate fractional Josephson effect
• Coexistence of topological and nontopological Fermi-superfluid phases
• Spin relaxation, Josephson effect and Yu-Shiba-Rusinov states in superconducting bilayer graphene
• Logical Majorana zero modes in a nanowire network
• Atomic scale imaging of sign-changing order parameter in superconducting FeSe with Tunneling Andreev Reflection
• Long-range coupling between superconducting dots induced by periodic driving
• Probing the topological band structure of diffusive multiterminal Josephson junction devices with conductance measurements
• Atomistic modeling of a superconductor-transition-metal dichalcogenide-superconductor Josephson junction
• Conductance asymmetry in proximitized magnetic topological insulator junctions with Majorana modes
• Revisiting Andreev processes in superconductor-graphene-superconductor (SGS) Josephson junctions: Comparison with experimental results
• Fermionic Quantum Simulation on Andreev Bound State Superlattices
• Nonlocal Josephson diode effect in minimal Kitaev chains
• Effect of Andreev Processes on the Goos-Hänchen (GH) shift in the Graphene-Superconductor-Graphene (GSG) junctions
• Nonequilibrium Andreev resonances in ballistic graphene Andreev interferometers
• Implementation of SNS thermometers into molecular devices for cryogenic thermoelectric experiments
• P-wave pairing near a spin-split Josephson junction
• Quantum size effects on Andreev transport in Nb/Au/Nb Josephson junctions: A combined ab-initio and experimental study
• Persistent current noise in narrow Josephson junctions
• Direct observation of intrinsic surface magnetic disorder in amorphous superconducting films
• Particle-hole spectral asymmetry at the edge of multiorbital noncentrosymmetric superconductors
• Quantum-size effect induced Andreev bound states in ultrathin metallic islands proximitized by a superconductor
• Andreev bound states at boundaries of polarized 2D Fermi superfluids with s-wave pairing and spin-orbit coupling
• SNS Junctions along the BCS-BEC Crossover
• The Josephson effect in Fibonacci superconductors
• Giant oscillatory Gilbert damping in superconductor/ferromagnet/superconductor junctions
• Local energy density functional for superfluid Fermi gases from effective field theory
• Open quantum dynamics of Josephson charge pumps
• Gaplessness from disorder and quantum geometry in gapped superconductors
• Giant and robust Josephson diode effect in multiband topological nanowires