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Related papers: Two band superconductivity in MgB2: basic anisotro…

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Molybdenum ditelluride (MoTe$_2$) is attracting considerable interest since it is the archetypal type-II Weyl semimetal and a candidate for topological superconductivity. We investigate the superconducting phase diagram of two MoTe$_2$…

Superconductivity · Physics 2021-09-13 Hari Paudyal , Samuel Poncé , Feliciano Giustino , Elena R. Margine

The intrinsic properties of MgB$_2$ form the basis for all applications of this superconductor. We wish to emphasize that the application range of polycrystalline MgB$_2$ is limited by the upper critical field H$_{c2}$ and its anisotropy.…

Superconductivity · Physics 2009-11-11 M. Eisterer , C. Krutzler , H. W. Weber

While the layered 122 iron arsenide superconductors are highly anisotropic, unconventional, and exhibit several forms of electronic orders that coexist or compete with superconductivity in different regions of their phase diagrams, we find…

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 synthesized single crystalline and policrystalline MgB_2 under ambient pressures. The single crystals of MgB_2 were of good quality, where the crystal structure refinements were successfully converged with R = 0.020. The specific heat of…

Superconductivity · Physics 2009-11-07 Y. Machida , S. Sasaki , H. Fujii , M. Furuyama , I. Kakeya , K. Kadowaki

The discovery of superconductivity at 39 K in MgB2[1] raises many issues. One of the central questions is whether this new superconductor resembles a high-temperature-cuprate superconductor or a low-temperature metallic superconductor in…

Eliashberg theory is used to investigate the range of thermodynamic properties possible within a two-band model for s-wave superconductivity and to identify signatures of its two-band nature. We emphasize dimensionless BCS ratios (those for…

Superconductivity · Physics 2009-11-10 E. J. Nicol , J. P. Carbotte

Samples of aligned MgB2 crystallites have been prepared, allowing for the first time the direct identification of an upper critical field anisotropy Hc2^{ab}/Hc2^{c}= xi_{ab}/xi_{c} ~ 1.73; with xi_{o,ab} ~ 70 A, xi_{o,c} ~ 40 A, and a mass…

Superconductivity · Physics 2009-11-07 O. F. de Lima , R. A. Ribeiro , M. A. Avila , C. A. Cardoso , A. A. Coelho

We carried out the measurements of magnetoresistance, magnetic susceptibility and specific heat on crystals of the low-dimensional transition metal telluride Ta$_4$Pd$_3$Te$_{16}$. Our results indicate that Ta$_4$Pd$_3$Te$_{16}$ is an…

Superconductivity · Physics 2015-07-29 Wen-He Jiao , Yi Liu , Yu-Ke Li , Xiao-Feng Xu , Jin-Ke Bao , Chun-Mu Feng , Shi-Yan Li , Zhu-An Xu , Guang-Han Cao

The magnetic penetration depth, $\lambda^{-2}(T)$, in the basal plane of a magnesium diboride (MgB$_2$) film was measured using a two-coil mutual inductance technique at 50 kHz. This film has $T_c\simeq 38$ K, $\Delta T_c \leq 1$ K, and…

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

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

Multiband superconductivity arises when multiple electronic bands contribute to the formation of the superconducting state, allowing distinct pairing interactions and gap structures. Here, we present field- and temperature-dependent data on…

Superconductivity · Physics 2025-05-08 A. Alshemi , E. M. Forgan , A. Hiess , R. Cubitt , J. S. White , K. Schmalzl , E. Blackburn

The temperature dependence of the upper critical magnetic field (Hc2) in a BaFe1.84Co0.16As2 single crystal was determined via resistivity, for the inter-plane (H^ab) and in-plane (H//ab) directions in pulsed and static magnetic fields of…

Superconductivity · Physics 2015-05-13 M. Kano , Y. Kohama , D. Graf , F. F. Balakirev , A. S. Sefat , M. A. McGuire , B. C. Sales , D. Mandrus , S. W. Tozer

We present results of in field directional point contact spectroscopy (DPCS) study in the quaternary borocarbide superconductor YNi2B2C, which is characterized by a highly anisotropic superconducting gap function. For I||a, the…

Superconductivity · Physics 2007-05-23 S Mukhopadhyay , Goutam Sheet , P Raychaudhuri , H Takeya

The field dependence of the magnetization above the transition temperature Tc in MgB₂ is shown to evidence a diamagnetic contribution consistent with superconducting fluctuations reflecting both the σ and π bands. In…

Superconductivity · Physics 2009-11-11 L. Romano' , A. Lascialfari , A. Rigamonti , I. Zucca

We report and analyze reversible magnetization measurements on a high quality MgB2 single crystal in the vicinity of the zero field transition temperature, T_c=38.83 K, at several magnetic fields up to 300 Oe, applied along the c-axis.…

Superconductivity · Physics 2009-01-14 S. Weyeneth , T. Schneider , N. D. Zhigadlo , J. Karpinski , H. Keller

Despite numerous studies the exact nature of the order parameter in superconducting Sr2RuO4 remains unresolved. We have extended previous small-angle neutron scattering studies of the vortex lattice in this material to a wider field range,…

Since the discovery of MgB2 with Tc=39K, various metal diborides of MB2 have been intensively studied to find possible conventional high-temperature superconductors. A possible 2D structure of the metal diboride has been shown to be in the…

Superconductivity · Physics 2024-12-19 Jakkapat Seeyangnok , Udomsilp Pinsook , Graeme John Ackland

Highly dense MgB2 policrystalline bulk materials, obtained by reactive liquid infiltration, have been characterized in their superconducting transport and magnetic properties in magnetic field and in a temperature range of interest for the…

Superconductivity · Physics 2007-05-23 G. Giunchi , S. Ceresara , L. Martini , V. Ottoboni , S. Chiarelli , M. Spadoni