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Related papers: Scanning Tunneling Spectroscopy in MgB 2

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We have synthesized MgB2/Pb planar junctions to study the temperature and field dependence of the superconducting energy gap of MgB2. The major peak occurs at Delta of about 2 meV, and this corresponds to a 2Delta/kBTc value of 1.18. While…

Superconductivity · Physics 2009-11-07 Mohamed H. Badr , K. -W. Ng

We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB$_{2}$. Experiments are proposed which lead to identification of the possible scenarios: whether both $\sigma $- and $\pi $-bands superconduct or $\sigma…

Superconductivity · Physics 2007-05-23 V. A. Ivanov , J. J. Betouras , F. M. Peeters

A series of MgB$_2$ thin films systematically disordered by neutron irradiation have been studied by Scanning Tunneling Spectroscopy. The c-axis orientation of the films allowed a reliable determination of local density of state of the…

Superconductivity · Physics 2015-06-25 R. Di Capua , H. U. Aebersold , C. Ferdeghini , V. Ferrando , P. Orgiani , M. Putti , M. Salluzzo , R. Vaglio , X. X. Xi

Point contact junctions made from two pieces of MgB2 can be adjusted to exhibit either superconductor-insulator-superconductor (SIS) or superconductor-normal metal-superconductor (SNS) current-voltage characteristics. The SIS…

Superconductivity · Physics 2009-11-07 Y. Zhang , D. Kinion , J. Chen , D. G. Hinks , G. W. Crabtree , John Clarke

It has recently been observed that MgB_2 is a superconductor with a high transition temperature. Here we propose a model of anisotropic s-wave superconductivity which consistently describes the observed properties of this compound,…

Superconductivity · Physics 2009-11-07 Stephan Haas , Kazumi Maki

The optical response of the two-band superconductor MgB$_2$ has been studied in the 0.7-4 THz range on films with very low impurity level. The effect of the high-energy $\sigma$-gap is observed in the ratio $R_S/R_N$ between the normal and…

Superconductivity · Physics 2009-11-13 M. Ortolani , P. Dore , D. Di Castro , A. Perucchi , S. Lupi , V. Ferrando , M. Putti , I. Pallecchi , C. Ferdeghini , X. X. Xi

We report the temperature dependent magnetic penetration depth $\lambda(T)$ and the superconducting critical field $H_{c2}(T)$ in a 500-nm MgB$_{2}$ film. Our analysis of the experimental results takes into account the two gap nature of the…

We have performed a comparative study of two thin films of magnesium diboride (MgB2) grown by different techniques. The critical current density at different temperatures and magnetic fields was evaluated from magnetisation curves, the…

We present the first results of directional point-contact measurements in Mg_{1-x}Mn_{x}B_2 single crystals, with x up to 0.015 and bulk T_c down to 13.3 K. The order parameters Delta_{sigma} and Delta_{pi} were obtained by fitting the…

Recently RuB$_2$ was shown to be a possible two-gap, type-I superconductor. Temperature dependent heat capacity measurements revealed a two-gap superconducting ground state while magnetic field dependent magnetization measurements indicated…

Superconductivity · Physics 2020-06-24 Soumya Datta , Aastha Vasdev , Soumyadip Halder , Jaskaran Singh , Yogesh Singh , Goutam Sheet

We report the results of the first directional point-contact measurements in Mg(B_{1-x}C_{x})_2 single crystals with 0.047 <= x <= 0.132. The two-gap superconductivity typical of MgB_2 persists up to x=0.105. In this region, the values of…

Scanning tunneling microscopy (STM) is perhaps the most promising way to detect the superconducting gap size and structure in the canonical unconventional superconductor Sr$_2$RuO$_4$ directly. However, in many cases, researchers have…

Superconductivity · Physics 2024-12-02 Adrian Valadkhani , Jonas B. Profe , Andreas Kreisel , P. J. Hirschfeld , Roser Valentí

We present the ultralow-temperature thermal conductivity measurements on single crystals of transition-metal dichalcogenide material 4Hb-TaS$_{2}$, which has recently been proposed as a topological superconductor candidate. In zero field, a…

The Andreev reflection measurements of the superconducting energy gap in the carbon-substituted MgB$_2$ are presented. Despite the strong suppression of the transition temperature by 17 K in comparison with the pure MgB$_2$, the same…

Superconductivity · Physics 2009-11-10 P. Samuely , Z. Holanova , P. Szabo , J. Kacmarcik , R. A. Ribeiro , S. L. Bud'ko , P. C. Canfield

Superconducting micro-constrictions between Nb tips and high quality MgB$_{2}$ pellets have been realized by means of a point-contact inset, driven by a micrometric screw. Measurements of the current-voltage characteristics and of the…

The progress in investigation of two-band superconductor MgB$_2$ by the point-contact spectroscopy (PCS) is given. Results of study of superconducting gap temperature and magnetic field dependence for two-dimensional $\sigma$ and…

Superconductivity · Physics 2007-05-23 I. K. Yanson , Yu. G. Naidyuk

Electronic Raman scattering studies on MgB2 single crystals as a function of excitation and polarization have revealed three distinct superconducting features: a clean gap below 37 cm-1 and two coherence peaks at 109 cm-1 and 78 cm-1 which…

Superconductivity · Physics 2007-10-16 G. Blumberg , A. Mialitsin , B. S. Dennis , N. D. Zhigadlo , J. Karpinski

Sandwich-type MgB2 Josephson tunnel junctions (MgB2/AlOx/MgB2) have been fabricated using as-grown MgB2 films formed by molecular beam epitaxy. The junctions exhibited substantial supercurrent and a well-defined superconducting gap…

Superconductivity · Physics 2007-05-23 K. Ueda , S. Saito , K. Semba , T. Makimoto , M. Naito

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…

Using scanning tunneling spectroscopy at T = 4.2 K, we perform simultaneously the topographic imaging and the quasiparticle density of states (DOS) mapping in granular MgB2. We observe a new type of spectrum, showing a pronounced double…

Superconductivity · Physics 2009-11-07 F. Giubileo , D. Roditchev , W. Sacks , R. Lamy , J. Klein