SU(4) Symmetry Breaking and Induced Superconductivity in Graphene Quantum Hall Edges
arXiv:2306.12483 · doi:10.1103/PhysRevB.110.024518
Abstract
In graphene, the approximate SU(4) symmetry associated with the spin and valley degrees of freedom in the quantum Hall (QH) regime is reflected in the 4-fold degeneracy of graphene's Landau levels (LL's). Interactions and the Zeeman effect break such approximate symmetry and lift the corresponding degeneracy of the LLs. We study how the breaking of the approximate SU(4) symmetry affects the properties of graphene's QH edge modes located in proximity to a superconductor. We show how the lifting of the 4-fold degeneracy qualitatively modifies the transport properties of the QH-superconductor heterojunction. For the zero LL, by placing the edge modes in proximity to a superconductor, it is in principle possible to realize a 1D topological superconductor supporting Majoranas in the presence of sufficiently strong Zeeman field. We estimate the topological gap of such a topological superconductor and relate it to the properties of the QH-superconductor interface.
arXiv comment12 pages, 7 figures
References in corpus (54)
- Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
- Unpaired Majorana fermions in quantum wires
- Electronic transport in two dimensional graphene
- Kwant: a software package for quantum transport
- Electronic Properties of Graphene in a Strong Magnetic Field
- Quantum Hall Ferromagnetism in Graphene
- Majorana Fermions in Semiconductor Nanowires
- Spin and valley quantum Hall ferromagnetism in graphene
- Exotic non-Abelian anyons from conventional fractional quantum Hall states
- Universal topological quantum computation from a superconductor/Abelian quantum Hall heterostructure
- Tunable symmetry breaking and helical edge transport in a graphene quantum spin Hall state
- Edge States and the Quantized Hall Effect in Graphene
- Supercurrent in the quantum Hall regime
- Collective Modes and Skyrmion Excitations in Graphene SU(4) Quantum Hall Ferromagnets
- Phase diagram for the quantum Hall state in monolayer graphene
- Inducing Superconducting Correlation in Quantum Hall Edge States
- Visualizing Broken Symmetry and Topological Defects in a Quantum Hall Ferromagnet
- Quantum Hall effect in graphene with superconducting electrodes
- Field-induced Kosterlitz-Thouless transition in the N=0 Landau level of graphene
- Andreev Reflection in Strong Magnetic Fields
- Theory of the Magnetic-Field-Induced Insulator in Neutral Graphene
- Long-Distance Spin Transport Through a Graphene Quantum Hall Antiferromagnet
- Imaging tunable quantum Hall broken-symmetry orders in graphene
- Majorana Zero Modes in Graphene
- Electrical generation and detection of spin waves in a quantum Hall ferromagnet
- Spin-triplet supercurrent carried by quantum Hall edge states through a Josephson junction
- Interference of chiral Andreev edge states
- Andreev reflection in the fractional quantum Hall state
- Fractional and integer quantum Hall effects in the zeroth Landau level in graphene
- SU(N) Quantum Hall Skyrmions
- Annihilation of colliding Bogoliubov quasiparticles reveals their Majorana nature
- Andreev reflection and cyclotron motion at superconductor -- normal-metal interfaces
- Crossed Andreev effects in two-dimensional quantum Hall systems
- Induced superconducting pairing in integer quantum Hall edge states
- Edge State Induced Andreev Oscillation in Quantum Anomalous Hall Insulator-Superconductor Junctions
- Spin Superfluidity in the Quantum Hall State of Graphene
- Perfect crossed Andreev reflection in Dirac hybrid junctions in the quantum Hall regime
- Lattice Pseudospin Model for Quantum Hall Bilayers
- Mechanisms of Andreev reflection in quantum Hall graphene
- Disorder in Andreev reflection of a quantum Hall edge
- Superconductivity and fermionic dissipation in quantum Hall edges
- Andreev transport in two-dimensional normal-superconducting systems in strong magnetic fields
- Strong-Magnetic-Field Magnon Transport in Monolayer Graphene
- Interlayer Exchange Interactions, SU(4) Soft Waves and Skyrmions in Bilayer Quantum Hall Ferromagnets
- Supercurrent-enabled Andreev reflection in a chiral quantum Hall edge state
- Edge structure of graphene monolayers in the ν = 0 quantum Hall state
- Loss and decoherence at the quantum Hall - superconductor interface
- Vortex-enabled Andreev processes in quantum Hall-superconductor hybrids
- Nonlocal superconducting correlations in graphene in the quantum Hall regime
- Chiral supercurrent through a quantum Hall weak link
- Topological -junctions from crossed Andreev reflection in the Quantum Hall regime
- Geometrical effects on the downstream conductance in quantum-Hall--superconductor hybrid systems
- Global phase diagram of charge neutral graphene in the quantum Hall regime for generic interactions
- Spin transport in a graphene normal-superconductor junction in the quantum Hall regime