Related papers: Crossovers and Phase Coherence in Cuprate Supercon…
Superconducting properties of metallic nano-wires may strongly depend on specific experimental conditions. Here we consider a setup where superconducting phase fluctuations are restricted at one point inside the wire and equilibrium…
It is very important to elucidate the mechanism of superconductivity for achieving room temperature superconductivity. This paper is a short review article on the mechanism of high-temperature superconductivity. In the first half of this…
Superconducting transition temperature is calculated for differently doped bilayer cuprates. Superexchange is assumed to be the dominating mechanism of high-temperature superconductivity, but the contribution from the phonon potential is…
We study the effect of inhomogeneity of the paring interaction or the background potential on the superconducting transition temperature, T_c. In the weak coupling BCS regime, we find that inhomogeneity which is incommensurate with the…
In this paper the fundamental parameters of high-$T_c$ superconductivity are shown to be connected to the statistics of pairons (hole pairs in their antiferromagnetic environment) on a square lattice. In particular, we study the density…
The finite-temperature phase diagram of the attractive Hubbard model is studied by means of the Dynamical Mean Field Theory. We first consider the normal phase of the model by explicitly frustrating the superconducting ordering. In this…
We show that the resistivity in each phase of the High-Tc cuprates is a special case of a general expression derived from the Kubo formula. We obtain, in particular, the T-linear behavior in the strange metal (SM) and upper pseudogap (PG)…
There is considerable evidence that the highest $T_c$ obtainable in a copper-oxide plane is limitted by the competition between two effects: On the one hand, as the concentration of doped-holes, $ x$, is increased, the pairing scale, which…
I investigate energy transfer in a donor-acceptor pair beyond weak system-bath coupling. I identify a transition from coherent to incoherent dynamics with increasing temperature, due to multi-phonon effects not captured by a standard…
It is demonstrated that the transition temperature (Tc) of high-Tc superconductors is determined by their layered crystal structure, bond lengths, valency properties of the ions, and Coulomb coupling between electronic bands in adjacent,…
Using as a model the Hubbard Hamiltonian we determine various basic properties of electron-doped cuprate superconductors like ${Nd}_{2-x}{Ce}_{x}{CuO}_{4}$ and ${Pr}_{2-x}{Ce}_{x}{CuO}_{4}$ for a spin-fluctuation-induced pairing mechanism.…
Superconductivity in the cuprates, discovered in the late 1980s and occurring at unprecedentedly high temperatures (up to about 140K) in about thirty chemically distinct families, continues to be a major problem in physics. In this article,…
In underdoped cuprates, T_c is thought to be determined by Cooper pair phase fluctuations because of the small superfluid density n_s. Experimentally, T_c is found to scale with n_s. The fluctuation-exchange approximation (FLEX) in its…
The interplay of competing orders is relevant to high-temperature superconductivity known to emerge upon suppression of a parent antiferromagnetic order typically via charge doping. How such interplay evolves at low temperature---in…
Several recent experiments have challenged the premise that cuprate high-temperature superconductors approach conventional Landau-BCS behavior in the high-doping limit. We argue, based on an analysis of their superconducting spectra, that…
We propose a unified magnetic phase diagram of cuprate superconductors. A new feature of this phase diagram is a broad intermediate doping region of quantum-critical, $z=1$, behavior, characterized by temperature independent $T_1T/T_{\rm…
It is argued that the dominant feature of the phase diagram of the high $T_c$ cuprates is the crossover to the pseudogap phase in the energy (temperature) region $E (T^*)$. We argue that this scale is determined by the effective…
The change-over from phase- to amplitude-fluctuation driven superconductivity is examined for a composite system of free electrons (Fermions with concentration n_F) and localized electron-pairs (hard-core Bosons with concentration n_B) as a…
We propose a scenario for superconductivity at strong electron-electron attractive interaction, in the case when the increase of the interaction strength promotes the nucleation of the local Cooper pairs and forms a state with a spatially…
There is growing evidence that the unconventional spatial inhomogeneities in the doped high-Tc superconductors are accompanied by the pairing of electrons, subsequent quantum phase transitions (QPTs), and condensation in coherent states. We…