Related papers: Prerequisite for superconductivity: appropriate sp…
The theory of superconductivity within the t-J model, as relevant for cuprates, is developed. It is based on the equations of motion for projected fermionic operators and the mode-coupling approximation for the self-energy matrix. The…
An understanding of spin excitations in cuprates is essential since the mechanism of high-T$_C$ superconductivity might be linked to spin fluctuations. Band calculations for long "1-dimensional" unit cells of La$_2$CuO$_4$ show that the…
A broad review of theoretical research work involving different types of microscopic mechanism in various classes of superconductors, carried out in our research group over a decade or so, is presented. These mechanisms include both…
We develop a detailed analysis of electron transport in normal diffusive conductors in the presence of proximity induced superconducting correlation. We calculated the linear conductance of the system and the profile of the electric field.…
The combination of spin-orbit coupling and superconductivity induces unconventional spin-triplet correlation in Ising superconductors. We theoretically investigate the spin transport through a normal metal-Ising superconductor junction,…
We present a coherent scenario for the physics of cuprate superconductors, which is based on a charge-driven inhomogeneity, i.e. the ``stripe phase''. We show that spin and charge critical fluctuations near the stripe instability of…
Superconductivity in the t-J model is studied by extending the recently introduced extremely correlated fermi liquid theory. Exact equations for the Greens functions are obtained by generalizing Gor'kov's equations to include extremely…
We propose that underdoped high $T_c$ superconductors are described by an algebraic spin liquid (ASL) at high energies, which undergoes a spin-charge recombination transition at low energies. The spin correlation in the ASL is calculated…
This work answers the basic questions of superconductivity in a question-and-answer format. We extend a basic hypothesis to various superconductors. This hypothesis is that superconductivity requires that the pairing gap locates around the…
We present the current-density functional theory for the superconductor immersed in the magnetic field. The order parameter of the superconducting state, transverse component of the paramagnetic current-density, and electron density are…
We study the interplay of spin and charge coherence in a single-level quantum dot. A tunnel coupling to a superconducting lead induces superconducting correlations in the dot. With full spin symmetry retained, only even-singlet…
The vortex lattice with the superconducting and normal state charge carriers fractions may be regarded as three independent subsystems mutually connected by interactions. The equation of motion for these three subsystems must be solved…
This work discusses theoretically the interplay between the superconducting and ferromagnetic proximity effects, in a diffusive normal metal strip in contact with a superconductor and a non-uniformly magnetized ferromagnetic insulator. The…
In this study, we investigate the spin susceptibility in the superconducting state of a multilayer system with a layer-dependent Rashba spin-orbit coupling, representing a locally non-centrosymmetric superconductor. We show that the charge…
How the superconductivity in unconventional superconductors emerges from the diverse mother normal states is still a big puzzle. Whatever the mother normal states are the superconductivity is {\em normal} with BCS-like behaviours of the…
We calculate the superconducting $T_c$ for a system which experiences Rashba spin-orbit interactions. Contrary to the usual case where the electron-electron interaction is assumed to be wave vector-independent, where superconductivity is…
We study the spin and charge accumulation in junctions between a superconductor and a ferromagnet or a normal metal in the presence of a Zeeman magnetic field, when the junction is taken out of equilibrium by applying a voltage bias. We…
A brief review is given on the current state of experimental and theoretical work in the field of heavy fermion superconductivity. Particular emphasis is placed on those experiments which demonstrate the presence of an unconventional order…
We summarize the present status of the theories of spin fluctuations in dealing with the anomalous or non-Fermi liquid behavior and unconventional superconductivity in strongly correlated electron systems around their magnetic instabilities…
The presence of charge order in high-transition-temperature copper oxides (high-Tc cuprates) was identified a decade ago. Now it is a universally observed order like the antiferromagnetic and the superconducting orders of the cuprates. The…