Related papers: The two-gap BCS model in the large-$N$ approximati…
Departures of thermodynamic properties of three-dimensional superfluid $^3$He from the predictions of BCS theory are analyzed. Attention is focused on deviations of the ratios $\Delta(T=0)/T_c$ and $[C_s(T_c)-C_n(T_c)]/C_n(T_c)$ from their…
We solve numerically various types of the gap equations developed in the relativistic BCS and generalized BCS framework, presented in part I of this paper. We apply the method for, not only the usual solid metal but also other physical…
The phase transition "Coulomb-confinement" in the U(1) regularized gauge theory is considered in the framework of dual Abelian Higgs model of scalar monopoles (shortly: Higgs monopole model). The effective potential analogous to the…
In a superconductor electrons form pairs despite the Coulomb repulsion as a result of an effective attractive interaction mediated by, for example phonons. In the present paper DeGennes' description of the dynamically screened Coulomb…
Within the BCS framework a multiband model with d-wave symmetry is considered. Generalized Fermi surface topologies via band overlapping are introduced. The band overlap scale is of the order of the Debye energy. The order parameters and…
The temperature dependence of the London penetration depth,lambda(T), was measured in both single crystal and polycrystalline MgB_2 samples by a high-resolution, radio frequency technique. A clear exponential temperature dependence of…
We compute unbiased spectral functions of the two-dimensional Hubbard model by extrapolating Green functions, obtained from determinantal quantum Monte Carlo simulations, to the thermodynamic and continuous time limits. Our results clearly…
The maximum value of the energy gap $\Delta\simeq 8\ meV$ and the ratio $2\delta/kT_c\simeq~2.5$ are determined for a high-temperature superconductor $\rm Bi_2Sr_2CaCu_2O_{8+y}$ by using point contacts. It was found that the…
According to the BCS theory the superconducting condensate develops in a single quantum mode and no Cooper pairs out of the condensate are assumed. Here we discuss a mechanism by which the successful mode inhibits condensation in…
High-Tc superconductivity in layered cuprates is described in a BCS-BEC formalism with linearly-dispersive s- and d-wave Cooper pairs moving in quasi-2D finite-width layers about the CuO_2 planes. This yields a closed formula for Tc…
The scalar field theory and the scalar electrodynamics quantized in the flat gap are considered. The dynamical effects arising due to the boundary presence with two types of boundary conditions (BC) satisfied by scalar fields are studied.…
We study the phase diagram of the 3-dimensional SU(2) + adjoint Higgs theory, and investigate to what extent it can be used as an effective theory of the 4-dimensional high-T SU(2) QCD. The relation between the parameters in 4 and 3…
The ability to simulate realistically the electronic structure of superconducting materials is important to understand and predict various properties emerging in both the superconducting topological and spintronics realms. We introduce a…
We report the equilibrium vortex phase diagram of a rotating two-band Fermi gas confined to a cylindrically symmetric parabolic trapping potential, using the recently developed finite-temperature effective field theory [Phys. Rev. A…
The effective potential is computed for two boson systems in one trap as a function of their two individual hyperadii and the distance between their centers. Zero-range interactions are used and only relative s-states are included.…
Detailed temperature dependence of both superconducting gaps was obtained directly by means of SnS-Andreev spectroscopy. The \Delta \sigma,\pi(T) -curves were shown to be deviated from standard BCS-like behavior, due to k-space proximity…
Experiments with ultracold atoms provide a highly controllable laboratory setting with many unique opportunities for precision exploration of quantum many-body phenomena. The nature of such systems, with strong interaction and quantum…
The effective potential obtained by loop expansion is usually not real in the range of field values explored by its minima during a phase transition. We apply the optimized perturbation theory in a fixed gauge to singlet scalar extensions…
We study the effect of the chemical potential on the results of the BCS theory of superconductivity. We assume that the pairing interaction is manifested between electrons of single-particle energies in an interval $[\mu - \hbar\omega_c,…
The pairing gap plays a fundamental role in the nuclear many-body problem and many large scale and accurate mass formula fits suggest the smooth nuclear mass dependence $\Delta \sim 6(1)~ A^{-1/3}~{\rm MeV}$ in the liquid drop model which…