Related papers: Pairing interactions induce antiferromagnetism in …
High-temperature superconductivity emerges in a host of different quantum materials, often in a region of the phase diagram where the electronic kinetic energy is comparable in magnitude with the electron-electron Coulomb repulsion.…
Unconventional superconductivity (SC) is said to occur when Cooper pair formation is dominated by repulsive electron-electron interactions, so that the symmetry of the pair wavefunction is other than isotropic s-wave. The strong, on-site,…
We propose a nonlocal theory of single-particle excitations. It is based on an off-diagonal effective medium and the projection operator method for treating the retarded Green function. The theory determines the nonlocal effective medium…
We study effects of the Coulomb repulsion on the electron-phonon interaction (EPI) in a model of cuprates at zero and finite doping. We find that antiferromagnetic correlations strongly enhance EPI effects on the electron Green's function…
We present a model for cuprate superconductivity based on the identification of an experimentally detected "local superconductor" as a charge 2 fermion pairing in a circular, stationary density wave. This wave acts like a highly correlated…
We consider the sub-gap physics of a hybrid double-quantum dot Cooper-pair splitter with large single-level spacings, in the presence of tunnelling between the dots and finite Coulomb intra- and inter-dot Coulomb repulsion. In the limit of…
We consider theoretically a $1D$-semiconducting wire with strong Rashba interaction in proximity with $s$-wave superconductor, driven into topological phase by external magnetic field. Additionally, we take into account on-site Coulomb…
We study the behavior of magnetic superconductors which involve a local attractive interaction between electrons, and a coupling between local moments and the electrons. We solve this `Hubbard-Kondo' model through a variational minimization…
We develop a self-consistent microscopic framework beyond mean-field theory for monolayer cuprate superconductivity. It couples fermionic quasiparticles with collective phase dynamics to treat the gap and superfluid stiffness. The phase…
Developing a theory of high-temperature superconductivity in copper oxides is one of the outstanding problems in physics. It is a challenge that has defeated theoretical physicists for more than twenty years. Attempts to understand this…
A consistent microscopic theory of superconductivity for strongly correlated electronic systems is presented within the extended t-J-V model where the intersite Coulomb repulsion and the electron-phonon interaction are taken into account.…
A two-sublattice spin-fermion model of ferrimagnetic spinel, with spin-$1/2$ itinerant electrons at the sublattice $A$ site and spin-$s$ localized electrons at the sublattice $B$ site is considered. The exchange between itinerant and…
The experimental results for ZrZn$_{2}$, URhGe, and in some pressure ranges also for UGe$_{2}$, have shown that the ferromagnetic superconductors are weak itinerant ferromagnets. Guided by these results we describe the phenomenon of…
The effect of the Coulomb repulsion of holes on the Cooper instability in an ensemble of spin-polaron quasiparticles has been analyzed, taking into account the peculiarities of the crystallographic structure of the CuO$_2$ plane, which are…
In superconductors, electrons bound into Cooper pairs conduct a dissipationless current. The strength of the Cooper pairs scales with the value of the critical transition temperature (Tc). In cuprate high-Tc superconductors, however, the…
It is well established that a correlated quantum impurity embedded in a metallic host can form the many-body Kondo state with itinerant electrons due to the effective antiferromagnetic coupling. Such effect is manifested spectroscopically…
I review recent work on magnetic dynamics of the high temperature superconductors using a model that combines two weakly interacting species of low-energy excitations: the antiferromagnetic spin waves which carry spin-1 and no charge, and…
In this study, the pairing mechanism for layered HTS materials based on attraction between electrons from adjacent layers is proposed. Initially, each layer has expanded Fermi sphere owing to ridged geometry. When the two layers are close…
Near a quantum-critical point in a metal strong fermion-fermion interaction mediated by a soft collective boson gives rise to incoherent, non-Fermi liquid behavior. It also often gives rise to superconductivity which masks the non-Fermi…
In several unconventional superconductors, the highest superconducting transition temperature $T_{c}$ is found in a region of the phase diagram where the antiferromagnetic transition temperature extrapolates to zero, signaling a putative…