English
Related papers

Related papers: Multiband model for tunneling in MgB2 junctions

200 papers

For a microscopic model of a Josephson junction the normal coordinates of the two junction Goldstone bosons are constructed and their dynamical spectrum is computed. The explicit dependence on the phase difference of the two superconductors…

Mathematical Physics · Physics 2009-11-11 B. Dierckx , A. Verbeure

The upper critical field Hc2(T) for MgB2 is analyzed in terms of single and multi-band Eliashberg models. The relatively high value of Hc2(0) in the range of 14 to 18 Tesla can be understood, if a strongly coupled subgroup of heavy…

Superconductivity · Physics 2007-05-23 S. V. Shulga , S. -L. Drechsler , H. Eschrig , H. Rosner , W. E. Pickett

We report on tunneling spectroscopy experiments in small grains of the new binary intermetallic superconductor MgB2. Experiments have been performed at 2.5 K using a low temperature scanning tunneling microscope. Good fit to the BCS model…

Superconductivity · Physics 2009-11-07 Gabino Rubio-Bollinger , Hermann Suderow , Sebastian Vieira

Motivated by the recent results on impurity effects in MgB2, we present a theoretical model for a two-band superconductor in which the character of quasiparticle motion is ballistic in one band and diffusive in the other. We apply our model…

Superconductivity · Physics 2009-11-11 K. Tanaka , D. F. Agterberg , J. Kopu , M. Eschrig

We analyze the properties of flat-band superconductor junctions that behave differently from ordinary junctions containing only metals with Fermi surfaces. In particular, we show how in the tunneling limit the critical Josephson current…

Superconductivity · Physics 2025-09-08 P. Virtanen , R. P. S. Penttilä , P. Törmä , A. Díez-Carlón , D. K. Efetov , T. T. Heikkilä

We theoretically study the behavior of the critical current of a thermally-biased tunnel Josephson junction with a particular design, in which the electrodes of the junction are enclosed in two different superconducting loops pierced by…

Superconductivity · Physics 2022-07-20 Claudio Guarcello , Roberta Citro , Francesco Giazotto , Alessandro Braggio

We describe in this paper how the nonlinear Josephson inductance is the crucial circuit element for all Josephson qubits. We discuss the three types of qubit circuits, and show how these circuits use this nonlinearity in unique manners. We…

Superconductivity · Physics 2007-05-23 John M. Martinis , Kevin Osborne

We report scanning tunneling spectroscopy (STS) measurements of the gap properties of both ceramic MgB2 and c-axis oriented epitaxial MgB2 thin films. Both show a temperature dependent zero bias conductance peak and evidence for two…

Using a new cluster Monte Carlo algorithm, we study the phase diagram and critical properties of an interacting pair of resistively shunted Josephson junctions. This system models tunneling between two electrodes through a small…

Mesoscale and Nanoscale Physics · Physics 2009-09-29 Philipp Werner , Gil Refael , Matthias Troyer

We realized a time-domain simulator based on the electrodynamics of Cooper pairs and quasiparticles in Josephson junctions. The tool, based on the charge carriers' densities of states described by the Werthamer and Harris formalisms of…

Superconductivity · Physics 2023-05-03 Lucas Iwanikow , Pascal Febvre

Superconducting mechanism mediated by interband exchange Coulomb repulsion is examined in an extended two-band Hubbard models with a wide band crossing the Fermi level and coexisting with a narrower band located at moderately lower energy.…

Superconductivity · Physics 2007-05-23 Masatoshi Imada

We present a model of pressure effects of a two-band superconductor based on a Ginzburg-Landau free energy with two order parameters. The parameters of the theory are pressure as well as temperature dependent. New pressure effects emerge as…

Superconductivity · Physics 2009-11-10 J. J. Betouras , V. A. Ivanov , F. M. Peeters

We theoretically study the macroscopic quantum tunneling (MQT) in a hetero Josephson junction formed by a conventional single-gap superconductor and a multi-gap one such as ${MgB}_{2}$ and iron-based superconductors. In such a Josephson…

Quantum Physics · Physics 2011-02-11 Yukihiro Ota , Masahiko Machida , Tomio Koyama

Cryogenic scanning tunneling microscopy and magnetization measurements were used to study the superconducting properties of MgB_2. The magnetization measurements show a sharp superconductor transition onset at T_c = 38.5 K, in agreement…

Superconductivity · Physics 2009-11-07 Amos Sharoni , Israel Felner , Oded Millo

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…

Superconductivity · Physics 2024-03-14 Hiroyasu Koizumi

Solid MgB$_2$ has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first non-trivial application of a novel…

Exploiting the recently derived quantum Smoluchowski equation the classical Ivanchenko Zil'berman theory for overdamped diffusive phase motion of low capacitance Josephson junctions is extended to the low temperature quantum domain where…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Joachim Ankerhold

It is shown that the superconducting intermetallic compound MgB2 possesses a narrow, partly filled "superconducting band" with Wannier functions of special symmetry in its band structure. This result corroborates previous observations about…

Superconductivity · Physics 2011-03-03 Ekkehard Krüger

The theory of thermodynamic properties of two-band superconductor with reduced density charge carriers is developed on the base of phonon superconducting mechanism with strong electron-phonon interaction. This theory is adapted to describe…

Superconductivity · Physics 2015-06-25 M. E. Palistrant , V. A. Ursu

The microscopic theory of Josephson effect in point contacts between two-band superconductors is developed. The general expression for the Josephson current, which is valid for arbitrary temperatures, is obtained. We considered the dirty…

Superconductivity · Physics 2009-10-09 A. N. Omelyanchouk , Y. S. Yerin