Related papers: Unconventional high-temperature superconductivity …
Recent development in the physics of high-temperature cuprate superconductivity is reviewed, with special emphasis on the phenomena of unconventional and non-universal low-energy excitations of hole- and electron-type cuprate…
Correlations between electrons and the effective dimensionality are crucial factors that shape the properties of an interacting electron system. For example, the onsite Coulomb repulsion, U, may inhibit, or completely block the intersite…
Confirmation of the phononic origin of Cooper pair formation in superconductors came with the demonstration that the interaction was retarded and that the corresponding energy scales were associated with phonons. Using cellular dynamical…
A system of spinless fermions in $d=1+\epsilon$ dimensions, at zero-temperature and in random potential is studied using the perturbative renormalization group to first order in disorder and to second order in interaction. We find a…
A repulsive interaction model of superconductivity (SC) is studied for tight-binding models with three-fold degenerate molecular orbitals. Taking a weak-coupling approach, we derive dimensionless coupling constants for various symmetries of…
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.…
In this work we introduce the possibility of unparticle mediated superconductivity. We discuss a theoretical scenario where it can emerge and show that a superconducting state is allowed by deriving and solving the gap equation for $s$-wave…
Cooper pairing and Coulomb repulsion are antagonists, producing distinct energy gaps in superconductors and Mott insulators. When a superconductor exchanges unpaired electrons with a quantum dot, its gap is populated by a pair of…
We consider the problem of the superconductor-insulator transition in the presence of disorder, assuming that the fermionic degrees of freedom can be ignored so that the problem reduces to one of Cooper pair localization. Weak disorder…
Superconductivity had been one of the most enigmatic phenomena in condensed matter physics, puzzling the best theorists for 45 years, since the original discovery by Kamerlingh-Onnes in 1911 till the final solution by Bardeen, Cooper and…
Fermionic superfluidity with a nontrivial Cooper-pairing, beyond the conventional Bardeen-Cooper-Schrieffer state, is a captivating field of study in quantum many-body systems. In particular, the search for superconducting states with…
The two-dimensional boson-fermion model of high-temperature superconductors, numerically studied by Domanski (Phys. Rev. B v.66, 134512 (2002)) is not a superconductor. The critical temperature of the model is zero for any symmetry of the…
We study Hubbard models for ultracold bosonic or fermionic atoms loaded into an optical lattice. The atoms carry a high spin $F>1/2$, and interact on site via strong repulsive Van der Waals forces. Making convenient rearrangements of the…
The low-temperature thermoelectric power of the repulsive-interaction one-dimensional Hubbard model is calculated using an asymptotic Bethe ansatz for holons and spinons. The competition between the entropy carried by the holons and that…
In this paper, we argue that the high-temperature superconductors do not belong to strong correlated electron systems. It is shown that both the two-dimensional Hubbard and t-J models are inadequate for describing high temperature…
Studies of the superconducting proximity effect in normal conductor/superconductor $(N/S)$ junctions almost universally assume no effective electron-electron coupling in the $N$ region. While such an approximation leads to a simple…
The physical pictures of the electron pairing structure and pairing mechanisms in superconductors are reviewed. An initial idea for a new physical picture of the origin and nature of the pairing is proposed. The idea is based on the…
In systems with linear electron-phonon interaction (EPI), bound states of polarons, or bipolarons, form by gaining energy from the lattice deformation. The quadratic EPI case is fundamentally different: bipolarons form because electrons…
When the electron-phonon coupling is quadratic in the phonon coordinates, electrons can pair to form bipolarons due to phonon zero-point fluctuations, a purely quantum effect. We study superconductivity originating from this pairing…
We investigate a model many-body system of spinless Fermi gas in two dimensions, where the bare two-body interaction is repulsive and takes the form of a soft-core disk potential. We obtain the zero temperature phase diagram of this model…