Topological $\pi$-junctions from crossed Andreev reflection in the Quantum Hall regime

Abstract

We consider a two-dimensional electron gas (2DEG) in the Quantum Hall regime in the presence of a Zeeman field, with the Fermi level tuned to filling factor $\nu =1$. We show that, in the presence of spin-orbit coupling, contacting the 2DEG to a narrow strip of an s-wave superconductor produces a topological superconducting gap along the contact as a result of crossed Andreev reflection (CAR) processes across the strip. The sign of the topological gap, controlled by the CAR amplitude, depends periodically on the Fermi wavelength and strip width and can be externally tuned. An interface between two halves of a long strip with topological gaps of opposite sign implements a robust $\pi$-junction, hosting a pair of Majorana zero modes that do not split despite their overlap. We show that such a situation can be exploited to perform protected non-Abelian tunnel-braid operations without any fine tuning.

10 pages, 5 figures. Corrected minor errors, updated figures and references

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Cited by in corpus (16)

• From Andreev to Majorana bound states in hybrid superconductor-semiconductor nanowires
• Ballistic superconductivity and tunable $\pi$-junctions in InSb quantum wells
• Evidence for chiral supercurrent in quantum Hall Josephson junctions
• Perfect crossed Andreev reflection in Dirac hybrid junctions in the quantum Hall regime
• Even-odd effect and Majorana states in full-shell nanowires
• Formation and detection of Majorana modes in quantum spin Hall trenches
• Crossed Andreev reflection in spin-polarized chiral edge states due to the Meissner effect
• Transport signatures of Majorana bound states in superconducting hybrid structures
• Interaction-induced topological superconductivity in antiferromagnet-superconductor junctions
• Chiral Quasiparticle Tunneling Between Quantum Hall Edges in Proximity with a Superconductor
• SU(4) Symmetry Breaking and Induced Superconductivity in Graphene Quantum Hall Edges
• Spin transport in a graphene normal-superconductor junction in the quantum Hall regime
• Heat-charge separation in a hybrid superconducting quantum Hall setup
• Confinement-induced Majorana modes in a nodal topological superconductor
• Interedge backscattering in time-reversal symmetric quantum spin Hall Josephson junctions
• Limits of Thermal Conductance Quantization in Chiral Topological Josephson Junctions