Quasiclassical Theory of the Josephson Effect in Ballistic Graphene Junctions

  title={Quasiclassical Theory of the Josephson Effect in Ballistic Graphene Junctions},
  author={Yositake Takane and Ken-Ichiro Imura},
  journal={Journal of the Physical Society of Japan},
  • Y. TakaneK. Imura
  • Published 16 August 2012
  • Physics
  • Journal of the Physical Society of Japan
The stationary Josephson effect in a system of ballistic graphene is studied in the framework of quasiclassical Green's function theory. Reflecting the ultimate two-dimensionality of graphene, a Josephson junction involving a graphene sheet embodies what we call a planar Josephson junction, in which superconducting electrodes partially cover the two-dimensional graphene layer, achieving a planar contact with it. For capturing this feature we employ a model of tunneling Hamiltonian that also… 

Figures from this paper

Short Ballistic Josephson Coupling in Planar Graphene Junctions with Inhomogeneous Carrier Doping.

This work reports on short ballistic Josephson coupling in junctions embedded in a planar heterostructure of graphene and argues that this feature stems from the effects of inhomogeneous carrier doping in graphene near the superconducting contacts, although the junction is in fact in the short-junction limit.

Effect of dilute impurities on short graphene Josephson junctions

Despite the structural simplicity of graphene, its mechanical and electronic remarkable properties make this material a credible starting point for new technologies across a wide range of fields. The

Proximity coupling in superconductor-graphene heterostructures

The phase-sensitive properties and phase-particle dynamics of graphene Josephson junctions are examined to provide an understanding of the underlying mechanisms of Josephson coupling via graphene.

1/f critical current noise in short ballistic graphene Josephson junctions

Short ballistic graphene Josephson junctions sustain superconducting current with a non-sinusoidal current-phase relation up to a critical current threshold. The current-phase relation, arising from

Proximity-induced superconductivity in single-layer and bilayer graphene

In this work, the properties of proximity-induced superconductivity in graphene and bilayer graphene are investigated. First, we present the study of a junction consisting of a graphene sheet

DC Self-Field Critical Current in Superconductor/ Dirac-Cone Material/Superconductor Junctions

The ballistic model, which is traditionally considered to be a basic model to describe Ic(sf,T) in S/DCM/S junctions, is shown to be an inadequate tool to analyze experimental data from these type of junctions while Ambegaokar-Baratoff model provides good experimental data description.

DC Self-Field Critical Current in Superconductor/Dirac-Cone Material/Superconductor Junctions and The Request for Ballistic Model Reexamination

Recently, several research groups have reported on anomalous enhancement of the self-field critical currents, Ic(sf,T), at low temperatures in superconductor/Dirac-cone material/superconductor



Josephson Current through a Planar Junction of Graphene

Josephson effect in a planar graphene junction is studied by assuming that the coupling of a graphene sheet and two superconductors deposited on its top is described by a tunneling Hamiltonian. This

Josephson current in ballistic superconductor-graphene systems

We calculate the phase, the temperature and the junction length dependence of the supercurrent for ballistic graphene Josephson junctions. For low temperatures we find nonsinusoidal dependence of the

Josephson current and multiple Andreev reflections in graphene SNS junctions

The Josephson effect and superconducting proximity effect were observed in superconductor-graphene-superconductor (SGS) Josephson junctions with coherence lengths comparable to the distance between

Chiral tunnelling and the Klein paradox in graphene

The so-called Klein paradox—unimpeded penetration of relativistic particles through high and wide potential barriers—is one of the most exotic and counterintuitive consequences of quantum

Self-consistent solution for proximity effect and Josephson current in ballistic graphene SNS Josephson junctions

We use a tight-binding Bogoliubov\char21{}de Gennes (BdG) formalism to self-consistently calculate the proximity effect, Josephson current, and local density of states in ballistic graphene

Bipolar supercurrent in graphene

Light is shed on the special role of time reversal symmetry in graphene, and phase coherent electronic transport at the Dirac point is demonstrated, finding that not only the normal state conductance of graphene is finite, but also a finite supercurrent can flow at zero charge density.

Tunneling Density of States in Multilayer Graphene Deposited on a Superconductor

The excitation spectrum of quasiparticles in multilayer graphene deposited on a superconductor is studied within the framework of the Bogoliubov–de Gennes equation under an effective mass

Orbital diamagnetism in multilayer graphenes : Systematic study with the effective mass approximation

We present a theoretical study on the orbital magnetism in multilayer graphenes within the effective mass approximation. The Hamiltonian and thus susceptibility can be decomposed into contributions