Supercurrent reversal in Josephson junctions based on bilayer graphene flakes

Abstract

We investigate the Josephson effect in a bilayer graphene flake contacted by two monolayer sheet deposited by superconducting electrodes. It is found that when the electrodes are attached to the different layers of the bilayer, the Josephson current is in a $\pi$ state when the bilayer region is undoped and in the absence of vertical bias. Applying doping or bias to the junction reveals $\pi -0$ transitions which can be controlled by varying the temperature and the junction length. The supercurrent reversal here is very different from the ferromagnetic Josephson junctions where the spin degree of freedom plays the key role. We argue that the scattering processes accompanied by layer and sublattice index change give rise to the scattering phases which their effect varies with doping and the bias. Such scattering phases are responsible for the $\pi -0$ transitions. On the other hand if both of the electrodes are coupled to the same layer of the flake or the flake has AA stacking instead of common AB, the junction will be always in $0$ state since layer or sublattice index is not changed.

8 pages, 5 figures

References in corpus (30)

• The electronic properties of graphene
• Chiral tunneling and the Klein paradox in graphene
• Biased bilayer graphene: semiconductor with a gap tunable by electric field effect
• Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene
• Gate-induced insulating state in bilayer graphene devices
• Electronic States of Graphene Nanoribbons
• Andreev reflection and Klein tunneling in graphene
• Asymmetry gap in the electronic band structure of bilayer graphene
• Bipolar supercurrent in graphene
• The electronic properties of bilayer graphene
• Specular Andreev reflection in graphene
• Ab Initio Theory of Gate Induced Gaps in Graphene Bilayers
• Probing the Electronic Structure of Bilayer Graphene by Raman Scattering
• Josephson effect in ballistic graphene
• Ballistic transmission through a graphene bilayer
• Transport Through Andreev Bound States in a Graphene Quantum Dot
• Transmission through a biased graphene bilayer barrier
• Electronic transport through bilayer graphene flakes
• Dirac-fermions and conductance-oscillations in (s,d)-wave superconductor/normal graphene junctions
• Transmission through a boundary between monolayer and bilayer graphene
• A supercurrent switch in graphene $\pi$-junctions
• Andreev reflection in graphene nanoribbons
• Friedel Oscillation-Induced Energy Gap Manifested as Transport Asymmetry at Monolayer-Bilayer Graphene Boundaries
• Dirac Green's function approach to graphene-superconductor junctions with well defined edges
• Long range Josephson coupling through ferromagnetic graphene
• Tunable Supercurrent at the Charge Neutrality Point via Strained Graphene Junctions
• Quantum Hall Effects in Monolayer-Bilayer Graphene Planar Junctions
• Anisotropic minimal conductivity of graphene bilayers
• Gate-controlled supercurrent reversal in MoS${}_2$-based Josephson junctions
• Electronic transmission in Graphene suppressed by interlayer interference

Cited by in corpus (4)

• Inter-layer and Intra-layer Heat Transfer in Bilayer/Monolayer Graphene van der Waals Heterostructure: Is There a Kapitza Resistance Analogous?
• Quantum transport across van der Waals domain walls in bilayer graphene
• Magnetic field oscillations of the critical current in long ballistic graphene Josephson junctions
• Anomalous quantum interference effects in graphene SNS junctions due to strain-induced gauge fields