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相关论文: Nature of bonding and electronic structure in MgB2…

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We review the current situation in the theory of superconducting and transport properties of MgB2. First principle calculations of of the electronic structure and electron-phonon coupling are discussed and compared with the experiment. We…

超导电性 · 物理学 2009-11-07 I. I. Mazin , V. P. Antropov

By means of density functional theory the electronic structure of the MgB2 superconductor was characterised and compared with that of the related iso-structural systems: AlB2, ZrB2, NbB2, and TaB2. Using the full-potential linearized…

超导电性 · 物理学 2009-11-07 Pablo de la Mora , Miguel Castro , Gustavo Tavizon

X-ray diffraction multipole refinements of single-crystalline Mg$_x$Al$_{1-x}$B$_2$ and polarization-dependent near-edge x-ray absorption fine structure at the B 1$s$ edge reveal a strongly anisotropic electronic structure. Comparing the…

超导电性 · 物理学 2016-04-01 M. Merz , P. Schweiss , Th. Wolf , H. v. Löhneysen , S. Schuppler

Motivated by the recent results on impurity effects in MgB2, we present a theoretical model for a two-band superconductor in which the character of quasiparticle motion is ballistic in one band and diffusive in the other. We apply our model…

超导电性 · 物理学 2009-11-11 K. Tanaka , D. F. Agterberg , J. Kopu , M. Eschrig

The accurate charge density of MgB2 was observed at room temperature(R.T.) and 15K by the MEM(Maximum Entropy Method)/Rietveld analysis using synchrotron radiation powder data. The obtained charge density clearly revealed the covalent…

材料科学 · 物理学 2009-11-07 E. Nishibori , M. Takata , M. Sakata , H. Tanaka , T. Muranaka , J. Akimitsu

We present the results of fully-relaxed, full-potential electronic structure calculations for the new superconductor MgB2, and BeB2, NaB2, and AlB2, using density-functional-based methods. Our results described in terms of (i) density of…

超导电性 · 物理学 2009-11-07 Prabhakar P. Singh

First principles FLMTO-GGA electronic structure calculations of the new medium-$T_C$ superconductor (MTSC) $MgB_2$ and related diborides indicate that superconductivity in these compounds is related to the the existence of $p_{x,y}$-band…

超导电性 · 物理学 2009-11-07 N. I. Medvedeva , A. L. Ivanovskii , J. E. Medvedeva , A. J. Freeman

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…

超导电性 · 物理学 2009-11-07 J. Kortus , I. I. Mazin , K. D. Belashchenko , V. P. Antropov , L. L. Boyer

The band structure and the Fermi surface of hexagonal diborides ZrB2, VB2, NbB2, TaB2 have been studied by the self-consistent full-potential LMTO method and compared with those for the isostructural superconductor MgB2. Factors responsible…

超导电性 · 物理学 2007-05-23 I. R. Shein , A. L. Ivanovskii

A series of calculations on MgB2 and related isoelectronic systems indicates that the layer of Mg(2+) ions lowers the non-bonding B "pi" (p_z) bands relative to the bonding "sigma" (sp_xp_y) bands compared to graphite, causing sigma --> pi…

超导电性 · 物理学 2009-11-07 J. M. An , W. E. Pickett

It is shown that the superconducting intermetallic compound MgB2 possesses a narrow, partly filled "superconducting band" with Wannier functions of special symmetry in its band structure. This result corroborates previous observations about…

超导电性 · 物理学 2011-03-03 Ekkehard Krüger

We report first-principles calculations of the electronic band structure and lattice dynamics for the new superconductor MgB$_{2}$. The excellent agreement between theory and our inelastic neutron scattering measurements of the phonon…

Superconducting mechanism mediated by interband exchange Coulomb repulsion is examined in an extended two-band Hubbard models with a wide band crossing the Fermi level and coexisting with a narrower band located at moderately lower energy.…

超导电性 · 物理学 2007-05-23 Masatoshi Imada

In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent…

Recently, a honeycomb borophene was reported to grow successfully on Al(111) surface. Since the metallic $\sigma$-bonding bands of honeycomb boron sheet play a crucial role in the 39 K superconductivity of MgB$_2$, it is physically…

超导电性 · 物理学 2019-07-12 Miao Gao , Xun-Wang Yan , Jun Wang , Zhong-Yi Lu , Tao Xiang

The optical conductivity of MgB$_2$ has been determined on a dense polycrystalline sample in the spectral range 6 meV - 4.6 eV using a combination of ellipsometric and normal incidence reflectivity measurements. $\sigma_{1}(\omega)$…

According to the crystal structure of MgB$_{2}$ and band structure calculations quasi-two-dimensional (2D) boron planes are responsible for the superconductivity. We report on critical fields and resistance measurements of 30 nm thick…

超导电性 · 物理学 2009-11-07 A. S. Sidorenko , L. R. Tagirov , A. N. Rossolenko , V. V. Ryazanov , R. Tidecks

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…

超导电性 · 物理学 2009-11-07 Hisatomo Harima

This study examines the potential of superconductivity in transition metal (TM) intercalated bilayer graphene through a systematic study of the electronic and magnetic properties. We determine the electronic structure for all first row TM…

In order to understand the unexpected superconducting behavior of MgB$_2$ compound we have made electronic structure calculations for MgB$_2$ and closely related systems. Our calculated Debye temperature from the elastic properties indicate…

超导电性 · 物理学 2009-11-07 P. Ravindran , P. Vajeeston , R. Vidya , A. Kjekshus , H. Fjellvåg
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