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Related papers: A first-principles study of MgB2 (0001) surfaces

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Ab initio calculations based on the density-functional pseudopotential approach have been used to study the fully relaxed structure, the electron distribution and the electronic density of states of (001) terraces, steps, corners and…

mtrl-th · Physics 2009-10-28 L. N. Kantorovich , J. M. Holender , M. J. Gillan

High resolution angle-resolved photoemission measurements have been carried out to study the electronic structure and superconducting gap of the (Tl$_{0.58}$Rb$_{0.42}$)Fe$_{1.72}$Se$_2$ superconductor with a T$_c$=32 K. The Fermi surface…

We present the results of measurements of the thermal and electrical conductivity in the basal plane of single-crystalline MgB_2 between 2 and 300 K. The analysis of the temperature dependence of the thermal conductivity gives supporting…

Superconductivity · Physics 2007-05-23 A. V. Sologubenko , J. Jun , S. M. Kazakov , J. Karpinski , H. R. Ott

We have studied the structural and superconducting properties of MgB$_2$ thin films made by pulsed laser deposition followed by in situ annealing. The cross-sectional transmission electron microscopy reveals a nanocrystalline mixture of…

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

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

We characterize the superconducting state of phase pure polycrystalline samples of the new layered superconductor MgB$_2$ by specific heat measurements in magnetic fields up to 9 T. The characteristic jump at the superconducting transition…

Superconductivity · Physics 2007-05-23 R. K. Kremer , B. J. Gibson , K. Ahn

Energy band structures are calculated for the new superconductor MgB$_2$ and the related compounds by using the LDA and an FLAPW method. It is found that the strong three dimensional network in low-lying $\pi$ bands brings about two…

Superconductivity · Physics 2009-11-07 Hisatomo Harima

We present a polarization and topology resolved study of the low energy band structure in optimally doped superconducting Ba0.6K0.4Fe2As2 using angle resolved photoemission spectroscopy. Polarization-contrasted measurements allow us to…

Strongly Correlated Electrons · Physics 2009-12-31 L. A. Wray , D. Hsieh , Y. Xia , S. -Y. Xu , D. Qian , G. F. Chen , J. L. Luo , N. L. Wang , M. Z. Hasan

The heat capacity anomaly at the transition to superconductivity of the layered superconductor MgB$_2$ is compared to first-principles calculations with the Coulomb repulsion, $\mu^\ast$, as the only parameter which is fixed to give the…

Superconductivity · Physics 2009-11-07 A. A. Golubov , J. Kortus , O. V. Dolgov , O. Jepsen , Y. Kong , O. K. Andersen , B. J. Gibson , K. Ahn , R. K. Kremer

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 analyze superonductivity in MgB$_2$ observed below $T_c=39$ K resulting from electron-phonon coupling involving a mode at $\hbar \omega_1 = 24$ meV and most importantly the in-plane B-B $E_{2g}$ vibration at $\hbar \omega_2=67$ meV. The…

Superconductivity · Physics 2009-11-07 C. Joas , I. Eremin , D. Manske , K. H. Bennemann

We prepared MgB$_{2-x}$Be$_{x}$ ($x=0$, 0.2, 0.3, 0.4, and 0.6) samples where B is substituted with Be. MgB$_{2}$ structure is maintained up to $x=0.6$. In-plane and inter-plane lattice constants were found to decrease and increase,…

Superconductivity · Physics 2009-11-07 J. S. Ahn , Y. -J. Kim , M. -S. Kim , S. -I. Lee , E. J. Choi

A bulk superconductor possessing a topological surface state at the Fermi level is a promising system to realize long-sought topological superconductivity. Although several candidate materials have been proposed, experimental demonstrations…

Superconductivity · Physics 2018-02-07 K. Iwaya , Y. Kohsaka , K. Okawa , T. Machida , M. S. Bahramy , T. Hanaguri , T. Sasagawa

The electronic bandstructure of Au$_2$Pb has a Dirac cone which gaps when undergoing a structural transition into a low temperature superconducting phase. This suggests that the superconducting phase ($T_c=1.1$ K) might hold topological…

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…

This paper contains both recently published and original results concerning the electronic structure, bonding and relevant properties of (Mg-Al)B2. We analyse the electronic structure formation of bulk and surface states, study the nuclear…

Superconductivity · Physics 2007-05-23 V. P. Antropov , K. D. Belashchenko , M. van Schilfgaarde , S. N. Rashkeev

We present a comparison of electronic structure of MgB2 and TaB2, the two new superconductors, as well as VB2, calculated using full-potential, density- functional-based methods in P6/mmm crystal structure. Our results, described in terms…

Superconductivity · Physics 2007-05-23 Prabhakar P. Singh

Superconductor-insulator-superconductor tunnel junctions have been fabricated on MgB2 that display Josephson and quasiparticle currents. These junctions exhibit a gap magnitude, Delta~2.5 meV, that is considerably smaller than the BCS…

Superconductivity · Physics 2009-11-07 H. Schmidt , J. F. Zasadzinski , K. E. Gray , D. G. Hinks

We have measured the Raman spectra of polycrystalline MgB$_{2}$ from 25 {\cm} to 1200 {\cm}. When the temperature was decreased below the superconducting transition temperature $T_c$, we observed a superconductivity-induced redistribution…

Superconductivity · Physics 2016-08-31 X. K. Chen , M. J. Konstantinovic , J. C. Irwin , D. D. Lawrie , J. P. Franck