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Related papers: Scanning Tunneling Spectroscopy in MgB 2

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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

Detailed temperature dependence of both superconducting gaps was obtained directly by means of SnS-Andreev spectroscopy. The \Delta \sigma,\pi(T) -curves were shown to be deviated from standard BCS-like behavior, due to k-space proximity…

Superconductivity · Physics 2012-04-24 S. A. Kuzmichev , T. E. Shanygina , S. N. Tchesnokov , S. I. Krasnosvobodtsev

We present a method to produce superconducting tips to be used in Scanning Tunneling Microscopy/Spectroscopy experiments. We use these tips to investigate the evolution of the electronic density of states of NbSe2 from 0.3K up to its…

Superconductivity · Physics 2009-11-10 J. G. Rodrigo , S. Vieira

We present the results of the first directional point-contact spectroscopy experiments in high-quality MgB_2 single crystals. Due to the directionality of the current injection into the samples, the application of a magnetic field allowed…

Superconductivity · Physics 2009-11-07 R. S. Gonnelli , D. Daghero , G. A. Ummarino , V. A. Stepanov , J. Jun , S. M. Kazakov , J. Karpinski

The type I superconductor lead (Pb) has been theoretically predicted to be a two-band superconductor. We use scanning tunneling spectroscopy (STS) to resolve two superconducting gaps with an energy difference of 150$\,\mu$eV. Tunneling into…

Superconductivity · Physics 2015-04-22 Michael Ruby , Benjamin W. Heinrich , Jose I. Pascual , Katharina J. Franke

Tunneling spectroscopy played a central role in the experimental verification of the microscopic theory of superconductivity in the classical superconductors. Initial attempts to apply the same approach to high-temperature superconductors…

Superconductivity · Physics 2009-09-29 Oystein Fischer , Martin Kugler , Ivan Maggio-Aprile , Christophe Berthod , Christoph Renner

To establish the mechanism of unconventional superconductivity in Sr$_2$RUO$_4$, a prerequisite is direct information concerning the momentum-space structure of the energy gaps $\Delta_i(k)$, and in particular whether the pairing strength…

Superconductivity · Physics 2013-11-22 I. A. Firmo , S. Lederer , C. Lupien , A. P. Mackenzie , J. C. Davis , S. A. Kivelson

Using Scanning Tunneling Microscope at low temperature we explore the superconducting phase diagram in the $\pi$-band of the two-band superconductor MgB$_2$. In this band the peculiar shape of the local tunneling spectra and their dynamics…

Scanning tunneling spectroscopy was performed on single crystals of superconducting 2H-NbSe2, at 300 mK and in a magnetic field, up to 5 T, applied parallel to the ab-plane. This novel field geometry allows the quasiparticle…

Superconductivity · Physics 2011-11-01 I. Fridman , C. Kloc , J. Y. T. Wei

We have investigated a gap structure in a newly-discovered superconductor, MgB2 through the measurement of 11B nuclear spin-lattice relaxation rate, ^{11}(1/T_1). ^{11}(1/T_1) is proportional to the temperature (T) in the normal state, and…

Superconductivity · Physics 2009-11-07 H. Kotegawa , K. Ishida , Y. Kitaoka , T. Muranaka , J. Akimitsu

Magnesium diboride has many intriguing characteristics, including its relatively high critical temperature and two-band nature. Most prior studies of MgB2 thin film Josephson junctions have been conducted above 2 Kelvin. We report results…

Superconductivity · Physics 2015-05-20 Steve Carabello , Joseph Lambert , Jerome Mlack , Roberto Ramos

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

\beta-PdBi2 is one of the candidates for topological superconductors with a superconducting (SC) transition temperature (Tc) of 5.3 K, in which parity mixing of spin singlet and spin triplet has been anticipated, being crucial for the…

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,…

We consider the far-infrared and the microwave conductivities of a two-band superconductor with non-magnetic impurities. The strong coupling expressions for the frequency and temperature dependent conductivity of a two-band superconductor…

Superconductivity · Physics 2015-05-13 Bozidar Mitrovic

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

Interlayer tunneling spectroscopy measurements were performed on mesa arrays of Bi-2212 single crystals, intercalated with HgBr$_2$. Tunneling conductances were obtained over a wide temperature range to examine the spectral features,…

Superconductivity · Physics 2009-11-13 C. Kurter , D. Mazur , L. Ozyuzer , D. G. Hinks , K. E. Gray

The interplay of different emergent phenomena -- superconductivity (SC) and domain formation -- appearing on different spatial and energy scales are investigated using high-resolution scanning tunneling spectroscopy (STS) in the…

The tunneling conductance between a metal and a multiband s-wave superconductor with a thin layer of single-band s-wave superconductor sandwiched in between is examined in this paper. We show that an in-gap peak in conductance curve is…

Superconductivity · Physics 2013-05-29 Xiao-Yong Feng , Tai-Kai Ng

We performed the local spectroscopy of a Normal-metal--Superconductor (N-S) junction with the help of a very low temperature (60 mK) Scanning Tunneling Microscope (STM). The spatial dependence of the local density of states was probed…

Superconductivity · Physics 2009-11-07 N. Moussy , H. Courtois , B. Pannetier