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Related papers: Evidence for Two Superconducting Gaps in $MgB_2$

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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

Point-contact spectroscopy measurements on magnesium diboride reveal the existence of two superconducting energy gaps closing at the same transition temperature in line with the multiband model of superconductivity. The sizes of the two…

Superconductivity · Physics 2009-11-07 P. Samuely , P. Szabo , J. Kacmarcik , T. Klein , A. G. M. Jansen

We have studied the structure of the superconducting gap in MgB2 thin films by means of point-contact spectroscopy using a gold tip. The films were produced by depositing pure boron on a sapphire substrate, using e-beam evaporation,…

The superconducting gap of MgB2 has been studied by high-resolution angle-resolved photoemission spectroscopy (ARPES). The momentum(k)-resolving capability of ARPES enables us to identify the s- and p-orbital derived bands predicted from…

Superconductivity · Physics 2007-05-23 S. Tsuda , T. Yokoya , Y. Takano , H. Kito , A. Matsushita , F. Yin , H. Harima , S. Shin

We present extensive Scanning Tunneling Spectroscopy (STM/S) measurements at low temperatures in the multiband superconductor MgB$_2$. We find a similar behavior in single crystalline samples and in single grains, which clearly shows the…

Superconductivity · Physics 2009-11-07 P. Martinez-Samper , J. G. Rodrigo , G. Rubio-Bollinger , H. Suderow , S. Vieira , S. Lee , S. Tajima

Polarisation-resolved Raman scattering measurements were performed on MgB_2 single crystals to determine the magnitude, symmetry and temperature dependence of the superconducting gap. A single sharp peak due to Cooper pair breaking appears…

Superconductivity · Physics 2007-05-23 J. W. Quilty , S. Lee , A. Yamamoto , S. Tajima

We study the new binary intermetallic superconductor MgB2 using high-resolution photo-emission spectroscopy. The superconducting-state spectrum measured at 5.4 K shows a coherent peak with a shoulder structure, in sharp contrast to that…

Superconductivity · Physics 2009-11-07 S. Tsuda , T. Yokoya , T. Kiss , Y. Takano , K. Togano , H. Kitou , H. Ihara , S. Shin

Experimental support is found for the multiband model of the superconductivity in the recently discovered system MgB2 with the transition temperature Tc = 39 K. By means of Andreev reflection evidence is obtained for two distinct…

Superconductivity · Physics 2009-02-12 P. Szabo , P. Samuely , J. Kacmarcik , Th. Klein , J. Marcus , D. Fruchart , S. Miraglia , C. Marcenat , A. G. M. Jansen

We use tunable laser based Angle Resolved Photoemission Spectroscopy to study the electronic structure of the multi-band superconductor, MgB2. These results form the base line for detailed studies of superconductivity in multi-band systems.…

Superconductivity · Physics 2017-03-21 Daixiang Mou , Rui Jiang , Valentin Taufour , S. L. Bud'ko , P. C. Canfield , Adam Kaminski

The study of the anisotropic superconductor MgB2 using a combination of scanning tunneling microscopy and spectroscopy reveals two distinct energy gaps at Delta1=2.3 meV and Delta2=7.1 meV. Different spectral weights of the partial…

Superconductivity · Physics 2009-11-07 M. Iavarone , G. Karapetrov , A. E. Koshelev , W. K. Kwok , G. W. Crabtree , D. G. Hinks

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

We have performed high-resolution photoemission spectroscopy on MgB2 and observed opening of a superconducting gap with a narrow coherent peak. We found that the superconducting gap is s-like with the gap value of 4.5 meV at 15 K. The…

Strongly Correlated Electrons · Physics 2009-11-07 T. Takahashi , T. Sato , S. Souma , T. Muranaka , J. Akimitsu

Far-infrared reflectivity studies on the polycrystalline intermetallic compound MgB_2 with a superconducting transition temperature T_c=39 K were performed at temperatures 20 K to 300 K. We observe a significant raise of the…

We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a…

Superconductivity · Physics 2009-11-07 G. Karapetrov , M. Iavarone , W. K. Kwok , G. W. Crabtree , D. G. Hinks

We have analyzed about 100 voltage-dependent differential resistance dV/dI(V) curves of metallic point contacts between c-axis oriented MgB$_2$ thin film and Ag, which exhibit clear Andreev reflection features connected with the…

Starting from first principles, we show the formation and evolution of superconducting gaps in MgB$_2$ at its ultrathin limit. Atomically thin MgB$_2$ is distinctly different from bulk MgB$_2$ in that surface states become comparable in…

Superconductivity · Physics 2017-09-20 J. Bekaert , A. Aperis , B. Partoens , P. M. Oppeneer , M. V. Milosevic

The Raman spectrum of the superconductor MgB$_{2}$ has been measured as a function of the Tc of the film. A striking correlation is observed between the $T_{c}$ onset and the frequency of the $E_{2g}$ mode. Analysis of the data with the…

Superconductivity · Physics 2009-11-10 K. A. Yates , G. Burnell , N. A. Stelmashenko , D. -J. Kang , H. N. Lee , B. Oh , M. G. Blamire

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…

Boron in MgB_2 forms layers of honeycomb lattices with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with…

Superconductivity · Physics 2009-11-07 J. Kortus , I. I. Mazin , K. D. Belashchenko , V. P. Antropov , L. L. Boyer

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…

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