Related papers: Josephson coupling between superconducting islands…
We study the superconductor-insulator quantum phase transition in disordered Josephson junction chains. To this end, we derive the field theory from the lattice model that describes a chain of superconducting islands with a capacitive…
The ground and first excited state of two superconducting layers in interaction are studied considering two different coupling terms, one represented by the standard Josephson interaction, and one new, which is a superexchange pairing force…
We fabricate superconductor-graphene-superconductor Josephson junctions with superconducting regions made of lead (Pb). The critical current through grapehene may be modulated by external magnetic field; the resulting Fraunhofer…
The stationary Josephson current in a ballistic graphene system is theoretically studied with focus on a planar junction consisting of a monolayer graphene sheet on top of which a pair of superconducting electrodes is deposited. To…
Recently, a new theory of superconductivity has been put forward that attributes the origin of superconductivity to the appearance of a non-trivial Berry connection from many-electron wave functions. This theory reproduces the major results…
We studied the interlayer coupling and decoupling of bilayer graphene (BLG) by using spatially resolved electron energy loss spectroscopy (EELS) with a monochromated electron source. We correlated the twist-angle-dependent energy band…
We study a tunnel junction consisting of two thin-film s-wave superconductors separated by a thin, insulating barrier in the presence of misaligned in-plane exchange fields. We find an interesting interplay between the superconducting phase…
Motivated by a recent experiment directly measuring the current-phase relation (CPR) in graphene under the influence of a superconducting proximity effect, we here study the temperature dependence of the CPR in ballistic graphene SNS…
Superconducting hybrid junctions are revealing a variety of novel effects. Some of them are due to the special layout of these devices, which often use a coplanar configuration with relatively large barrier channels and the possibility of…
We theoretically study topological planar Josephson junctions (JJs) formed from spin-orbit-coupled two-dimensional electron gases (2DEGs) proximitized by two superconductors and subjected to an in-plane magnetic field $B_\parallel$.…
Recently, the Josephson diode effect (JDE), in which the superconducting critical current magnitudes differ when the currents flow in opposite directions, has attracted great interest. In particular, it was demonstrated that gate-defined…
We report on graphene-based Josephson junctions with contacts made from lead. The high transition temperature of this superconductor allows us to observe the supercurrent branch at temperatures up to $\sim 2$ K, at which point we can detect…
We calculate the dc Josephson current for two superconductor-ferromagnet (S/F) bilayers separated by a thin insulating film. It is demonstrated that the critical Josephson current $I_{c}$ in the junction strongly depends on the relative…
Unlike for tunneling Josephson junctions, for which the current-phase relation is given by the sine function, with the critical current ($I_c$) and normal-state resistance ($R_N$) following the relation $I_cR_N=(\pi/2)\,\Delta_0/e$ (where…
Motivated by recent experiments probing the wavefunctions of magic-angle twisted bilayer graphene (tBLG), we perform large-scale first-principles calculations of tBLG with full atomic relaxation across a wide range of twist angles down to…
The superconducting (SC) state of magic-angle twisted bilayer graphene (MATBG) shows exceptional properties, as it consists of an unprecedentedly small electron (hole) ensemble of only ~ 10 power 11 carriers per square centimeter, which is…
Since the discovery of the long-range superconducting proximity effect, the interaction between spin-triplet Cooper pairs and magnetic structures such as domain walls and vortices has been the subject of intense theoretical discussions,…
Proximity-induced superconductivity in three dimensional (3D) topological insulators forms a new quantum phase of matter and accommodates exotic quasiparticles such as Majorana bound states. One of the biggest drawbacks of the commonly…
We show that introducing spin-singlet or spin-triplet superconductivity into twisted bilayer graphene induces higher-order topological superconductivity. $C_{2z}T$-protected corner states of Majorana Kramers pairs appear at the boundary…
A range of twist angles between adjacent surfaces/volumes are intrinsic to natural graphite or artificially design in multi-layer graphene. In addition, stacking faults can be created by the application of mechanic, electric or magnetic…