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Related papers: Fermi surface topology and vortex state in MgB2

200 papers

Superconducting properties of hypothetical simple hexagonal CaB2 are studied using the fully anisotropic Eliashberg formalism based on electronic and phononic structures and electron-phonon interactions which are obtained from ab initio…

Superconductivity · Physics 2009-09-17 Hyoung Joon Choi , Steven G. Louie , Marvin L. Cohen

The Fermi surface anisotropy of a pseudo-gap in the spectral weight, caused by superconducting fluctuations or anti-ferromagnetic fluctuations, is calculated for a tight binding band. The importance of the Fermi surface saddle point, or hot…

Superconductivity · Physics 2016-11-29 L. Coffey

We report on temperature-dependent size and anisotropy of the Fermi pockets in graphite revealed by magnetotransport measurements. The magnetoresistances obtained in fields along the c-axis obey an extended Kohler's rule, with the carrier…

It was obtained the equation for the definition of upper critical field $% H_{c_2}$ in the system with two overlapping energetic bands on the Fermi surface, which is valid for the whole temperature interval $0 \leq T < T_c$. The analytic…

Superconductivity · Physics 2007-05-23 M. E. Palistrant

Metals with many bands at the Fermi level can have different band dependent gaps in the superconducting state. The absence of translational symmetry at an interface can induce interband scattering and modify the superconducting properties.…

Condensed Matter · Physics 2009-11-07 E. Bascones , F. Guinea

Magnetoresistivity measurements with fine tuning of the field direction on high quality single crystals of the ferromagnetic superconductor UCoGe show anomalous anisotropy of the upper critical field H_c2. H_c2 for H // b-axis (H_c2^b) in…

Strongly Correlated Electrons · Physics 2011-08-26 Dai Aoki , Tatsuma D. Matsuda , Valentin Taufour , Elena Hassinger , Georg Knebel , Jacques Flouquet

Despite the intense activity in the year since the discovery of superconductivity in MgB2, key parameters, in particular the upper and lower critical fields Hc2 and Hc1 and their anisotropies, are not well-established, largely because of…

Superconductivity · Physics 2009-11-07 G. K. Perkins , J. Moore , Y. Bugoslavsky , L. F. Cohen , J. Jun , S. M. Kazakov , J. Karpinski , A. D. Caplin

Magnetic-field-induced changes of the Fermi surface play a central role in theories of the exotic quantum criticality of YbRh2Si2. We have carried out de Haas-van Alphen measurements in the magnetic-field range 8 T <= H <= 16 T, and…

Strongly Correlated Electrons · Physics 2009-02-03 P. M. C. Rourke , A. McCollam , G. Lapertot , G. Knebel , J. Flouquet , S. R. Julian

We report first-principles calculations on the normal and superconducting state of CaBe(x)Si(2-x) (x=1), in the framework of density functional theory for superconductors (SCDFT). CaBeSi is isostructural and isoelectronic to MgB2 and this…

Superconductivity · Physics 2013-05-29 C. Bersier , A. Floris , A. Sanna , G. Profeta , A. Continenza , E. K. U. Gross , S. Massidda

The $g$-factor anisotropy of the heavy quasiparticles in the hidden order state of URu$_2$Si$_2$ has been determined from the superconducting upper critical field and microscopically from Shubnikov-de Haas (SdH) oscillations. We present a…

Strongly Correlated Electrons · Physics 2020-04-23 Gäel Bastien , Dai Aoki , Gérard Lapertot , Jean-Pascal Brison , Jacques Flouquet , Georg Knebel

We report small-angle neutron scattering measurements of the vortex lattice (VL) structure in single crystals of the lightly underdoped cuprate superconductor YBa2Cu3O6.85. At 2 K, and for fields of up to 16 T applied parallel to the…

We report measurements of the temperature dependent anisotropies ($\gamma_\lambda$ and $\gamma_\xi$) of both the London penetration depth $\lambda$ and the upper critical field of MgB$_2$. Data for $\gamma_\lambda=\lambda_c/\lambda_a$ was…

Superconductivity · Physics 2009-11-11 J. D. Fletcher , A. Carrington , O. J. Taylor , S. M. Kazakov , J. Karpinski

Investigations of MgB2 and Fe-based superconductors in recent years have revealed many unusual effects of multiband superconductivity but manifestations of anisotropic multiband effects in the critical current density Jc have not been…

Superconductivity · Physics 2014-12-10 A. A. Polyanskii , F. Kametani , D. Abraimov , A. Gurevich , A. Yamamoto , I. Pallecchi , M. Putti , C. Zhuang , T. Tan , X. X. Xi

We study a model for anisotropic singlet pairing in $A_3{\rm C}_{60}$, using a realistic model for the Fermi surface in a hypothesized orientationally-ordered doped crystal. Anisotropic solutions are studied by combining numerical solutions…

Condensed Matter · Physics 2009-10-22 E. J. Mele , S. C. Erwin

The temperature and angular dependence of the upper critical field (Hc2) is reported for cobalt-doped SrFe2As2 epitaxial films between Tc and 0.5 K in pulsed magnetic fields up to 50 T. For H parallel c, Hc2 is close to a linear function of…

Superconductivity · Physics 2009-04-12 S. A. Baily , Y. Kohama , H. Hiramatsu , B. Maiorov , F. F. Balakirev , M. Hirano , H. Hosono

We systematically measure the superconducting (SC) and mixed state properties of high-quality CsV3Sb5 single crystals with Tc ~ 3.5 K. We find that the upper critical field Hc2(T) exhibits a large anisotropic ratio of Hc2^(ab)/Hc2^(c) ~ 9…

The anisotropy of the magnetic field dependence of the specific heat of YBa$_2$Cu$_3$O$_{7 - {\rm \delta}}$ can be used to identify different low-energy excitations, which include phonons, spin-$ \frac{1}{2}$ particles, and electronic…

Condensed Matter · Physics 2009-10-28 Kathryn A. Moler , David J. Baar , Ruixing Liang , Walter N. Hardy , Aharon Kapitulnik

We consider the quasiparticle c-axis conductivity in highly anisotropic layered compounds in the presence of the magnetic field parallel to the layers. We show that at low temperatures the quasiparticle interlayer conductivity depends…

Superconductivity · Physics 2011-04-08 L. N. Bulaevskii , M. J. Graf , M. P. Maley

We theoretically study the dependence of the quasiparticle (QP) scattering rate $\varGamma$ on the uniaxial anisotropy of a Fermi surface with changing the magnetic field angle $\alpha_{\rm M}$. We consider the QP scattering due to the…

Superconductivity · Physics 2013-04-11 Yoichi Higashi , Yuki Nagai , Masahiko Machida , Nobuhiko Hayashi

We propose a quantum oscillation experiment by which the rotation of an underdoped YBa2Cu3O6+x sample about two different axes with respect to the orientation of the magnetic field can be used to infer the shape of the in-plane…

Superconductivity · Physics 2015-05-13 N. Harrison , R. D. McDonald