Related papers: Multiple-gap structure in electric-field-induced s…
Recently, a surface superconductor-insulator transition has been predicted for a bulk superconductor in an electric field applied perpendicular to its surface. The related calculations were performed within a one-dimensional Hubbard model…
In this article we review essential natures of superconductivity in strongly correlated electron systems (SCES) from a universal point of view. After summarizing experimental results on typical materials such as high-$T_{\rm c}$ cuprates,…
In this paper we study the effect of single non-magnetic impurity in two-band s-wave superconductors where the two s-wave order parameters have relative phase $\delta\neq0$ between them. We show that in-gap bound states are always induced…
The approach applicable for spatially inhomogeneous and time-dependent problems associated with the induced superconductivity in low dimensional electronic systems is developed. This approach is based on the Fano--Anderson model which…
The superconducting gap structure of a charge density wave (CDW) superconductor LaPt$_2$Si$_2$ ($T_c$ = 1.6~K) having a quasi two dimensional crystal structure has been investigated using muon spin rotation/relaxation ($\mu$SR) measurements…
We examine the effect of the magnetic field on the proximity effect in nanostructures, self consistently using the Bogoliubov-deGennes formalism within the two dimensional extended Hubbard model. We calculate the local density of states and…
Extended defects are known to strongly affect nanoscale superconductors. Here we report the properties of superconducting nanoribbons with a constriction formed between two adjacent step-edges, by solving the Bogoliubov-de Gennes equations…
Superconductivity induced structures in the electronic Raman spectra of high-Tc superconductors are computed using the results of ab initio LDA-LMTO three-dimensional band structure calculations via numerical integrations of the mass…
To determine the superconducting gap function of YNi2B2C, we calculate the local density of states (LDOS) around a single vortex core with the use of Eilenberger theory and the band structure calculated by local density approximation…
We report electronic structure calculations for BaTi$_2$Sb$_2$O and discuss the results in relation to the observed superconductivity of this material when hole doped with Na. The Fermi surface shows several sheets. These include a nested…
The local spectroscopic signatures of metamagnetic criticality in Sr3Ru2O7 were explored using scanning tunneling microscopy (STM). Singular features in the tunneling spectrum were found close to the Fermi level, as would be expected in a…
Normal state superconducting fluctuations are calculated for the case of a tight binding bandstructure. The resulting electronic self energy and spectral weight are anisotropic on the Fermi surface. For certain values of the chemical…
We present a theory for the pseudo-gap state recently observed at the LaAlO3/SrTiO3 interface, based on superconducting islands embedded in a metallic background. Superconductivity within each island is BCS-like, and the local critical…
We theoretically explore the possibility of a superconducting proximity effect in single-walled metallic carbon nanotubes due to the presence of a superconducting substrate. An unconventional double-gap situation can arise in the two bands…
We develop a theory of a pseudogap state appearing near the superconductor-insulator transition in strongly disordered metals with attractive interaction. We show that such an interaction combined with the fractal nature of the single…
A self-consistent Bogoliubov deGennes theory of the vortex lattice state in a 2D strong type-II superconductor at high magnetic fields reveals a novel quantum mixed state around the semiclassical Hc2, characterized by a well-defined…
Intrinsic tunneling spectroscopy in high magnetic field ($H$) is used for a direct test of superconducting features in a quasiparticle density of states of high-$T_c$ superconductors. We were able to distinguish with a great clarity two…
There have been an interesting debate on the primary source of chiral p-wave superconductivity in Sr2RuO4. We present a comparative study on the vortex structure between a single 2-dimensional (2D) band and quasi-1D band model by using…
We performed a high-resolution angle-resolved photoemission spectroscopy study on superconducting (SC) Tl$_{0.63}$K$_{0.37}$Fe$_{1.78}$Se$_2$ ($T_c=29$ K) in the whole Brillouin zone (BZ). In addition to a nearly isotropic $\sim$ 8.2 meV…
We study the electronic structure within a system of phase-decoupled one-dimensional superconductors coexisting with stripe spin and charge density wave order. This system has a nodal Fermi surface (Fermi arc) in the form of a hole pocket…