Valley-based Cooper Pair Splitting via Topologically Confined Channels in Bilayer Graphene

Abstract

Bilayer graphene hosts valley-chiral one dimensional modes at domain walls between regions of different interlayer potential or stacking order. When such a channel is brought into proximity to a superconductor, the two electrons of a Cooper pair which tunnel into it move in opposite directions because they belong to different valleys related by the time-reversal symmetry. This is a kinetic variant of Cooper pair splitting, which requires neither Coulomb repulsion nor energy filtering but is enforced by the robustness of the valley isospin in the absence of atomic-scale defects. We derive an effective model for the guided modes in proximity to an s-wave superconductor, calculate the conductance carried by split and spin-entangled electron pairs, and interpret it as a result of local Andreev reflection processes, whereas crossed Andreev reflection is absent.

7 pages, 3 figures

References in corpus (14)

• Valley filter and valley valve in graphene
• Andreev reflection and Klein tunneling in graphene
• The electronic properties of bilayer graphene
• Topological confinement in bilayer graphene
• Near-unity Cooper pair splitting efficiency
• Crossed Andreev reflection in a graphene bipolar transistor
• Cooper Pair Splitting by means of Graphene Quantum Dots
• Reversing non-local transport through a superconductor by electromagnetic excitations
• Spin-orbit coupling in a graphene bilayer and in graphite
• Detecting entangled states in graphene via crossed Andreev reflection
• Cooper-Pair Injection into Quantum Spin Hall Insulators
• Unconventional proximity-induced superconductivity in bilayer systems
• Unitary limit in crossed Andreev transport
• Trigonal distortion of topologically confined channels in bilayer Graphene

Cited by in corpus (13)

• Electronic properties of graphene-based bilayer systems
• Proximity coupling in superconductor-graphene heterostructures
• Crossed Andreev effects in two-dimensional quantum Hall systems
• Nonlocal transistor based on pure crossed Andreev reflection in a EuO-graphene/superconductor hybrid structure
• Signatures of nonlocal Cooper-pair transport and of a singlet-triplet transition in the critical current of a double-quantum-dot Josephson junction
• Zero-line modes at stacking faulted domain walls in multilayer graphene
• Topological valley transport at the curved boundary of a folded bilayer graphene
• Mesoscopic valley filter in graphene Corbino disk containing a p-n junction
• Topological phase transition induced by band structure modulation in a Chern insulator
• Signatures of interfacial topological chiral modes via RKKY exchange interaction in Dirac and Weyl systems
• Superconducting electron and hole lenses
• Electrically controlled crossover between $2\pi$- and $4\pi$-Josephson effects through topologically-confined channels in silicene
• Trigonal warping, pseudodiffusive transport, and finite-system version of the Lifshitz transition in magnetoconductance of bilayer-graphene Corbino disks