Related papers: BCS theory with the external pair potential
The BCS theory has achieved widespread success in describing conventional superconductivity. However, when the length scale reaches the atomic limit, the reduced dimensionality may lead to the quantum breakdown resulting in unpredictable…
The Ginzburg-Landau-Wilson theory that describes the disordered Fermi liquid - d-wave superconductor phase transition at zero temperature is derived at weak coupling. The theory represents an interacting dissipative system of bosonic Cooper…
The Landau expansion for the free energy of the superconducting mixed state near the upper critical field in powers of the square modulus of the order parameter averaged over Abrikosov lattice is derived. The analytical calculations has…
We investigate the influence of Landau Levels (LLs) and Zeeman energy, induced by an applied magnetic field ${\bf B}$, on the critical temperature $T_c$ for two-dimensional (2D) ultraclean metals using a fully quantum mechanical approach…
Understanding the pairing mechanism of unconventional superconductors remains a core challenge in condensed matter physics, particularly the ongoing debate over whether the related effects caused by electron-electron interactions unify…
A new theory for Cooper pair formation and superconductivity is derived from quantum statistical mechanics. It is shown that zero momentum Cooper pairs have non-local permutations and behave as effective bosons with an internal weight close…
We investigate superconductivity in a grand canonical ensemble with {\it fixed number parity} (even or odd). In the low temperature limit we find small corrections to the BCS gap equation and energy spectrum $E(k)$. The even-odd free energy…
The successful application of the electron-phonon interaction (EPI) mechanism in formulating the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity is among the most outstanding intellectual achievements in theoretical physics…
In the BCS theory of superconductivity, one assumes that all Cooper pairs have the same center of mass momentum. This is indeed enforced by self consistency, if the pairing interaction is momentum independent. Here, we show that for an…
We study the time evolution of a system of fermions with pairing interactions at a finite temperature. The dynamics is triggered by an abrupt increase of the BCS coupling constant. We show that if initially the fermions are in a normal…
This paper consists of three parts. In part I, we microscopically derive Ginzburg--Landau (GL) theory from BCS theory for translation-invariant systems in which multiple types of superconductivity may coexist. Our motivation are…
We apply the functional path-integral approach to analyze how the presence of a spin-orbit coupling (SOC) affects the basic properties of a BCS-type paired state in a two-component Bose gas. In addition to a mean-field theory that is based…
The Ginzburg-Landau theory of a trapped Fermi gas with a BEC-BCS crossover is derived by the path-integral method. In addition to the standard Ginzburg-Landau equation, a second equation describing the total atom density is obtained. These…
The recently proposed theoretical model of superconductors endowed with two distinct superconducting phases and critical temperatures is further analyzed by introducing two distinct order parameters, described by two scalar fields which…
The order parameter in superconductivity of cuprates is investigated in the framework of the Bogoliubov theory. By using a simplifying assumption about the electronic states, it is predicted an effective critical temperature Tc* > Tc…
It is shown that one can obtain quantitatively accurate values for the superconducting critical temperature within a Hamiltonian framework. This is possible if one uses a renormalized Hamiltonian that contains an attractive…
We present an analytically solvable theory of BCS-type superconductivity in good metals which are confined along one of the three spatial directions, such as thin films. Closed-form expressions for the dependence of the superconducting…
In the preceding papers the present author gave another proof of the existence and uniqueness of the solution to the BCS-Bogoliubov gap equation for superconductivity from the viewpoint of operator theory, and showed that the solution is…
BCS theory describes the formation of Cooper pairs and their instant "Bose condensation" into a superconducting state. Helium atoms are preformed bosons and, in addition to their condensed superfluid state, can also form a quantum solid,…
We have studied disorder effects on the coefficients of Ginzburg - Landau (GL) expansion for attractive Hubbard model within the generalized DMFT+Sigma approximation for the wide region of the values of attractive potential U - from the…