scholarly journals The Role of the Short Coherence Length in Unconventional Superconductors

2020 ◽  
Vol 5 (4) ◽  
pp. 77
Author(s):  
Guy Deutscher
Keyword(s):  
Coherence Length ◽  
Chemical Structure ◽  
Einstein Condensation ◽  
Unconventional Superconductors ◽  
Bose Einstein Condensation ◽  
Simple Chemical ◽  
Metal To Insulator Transition ◽  
Granular Superconductors ◽  
Bose Einstein

A short coherence length is a distinctive feature of many cases of unconventional superconductivity. While in conventional superconductors, it is many orders of magnitude larger than the basic inter-particle distance, a short coherence length is common to superconductors as diverse as the cuprates, the picnites and granular superconductors. We dwell particularly on the last, because their simple chemical structure makes them a favorable material for exploring fundamental phenomena such as the Bardeen-Cooper Schrieffer (BCS)-to-Bose–Einstein condensation cross-over and the effect of the vicinity of a Mott metal-to-insulator transition.

scholarly journals FLUCTUATION CONTRIBUTION TO THE SPECIFIC HEAT IN NON-FERMI MODELS FOR SUPERCONDUCTIVITY

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2988-2993
Author(s):  
I. Tifrea ◽  
I. Grosu ◽  
M. Crisan
Keyword(s):  
Crossover Study ◽  
Specific Heat ◽  
Green’S Function ◽  
Green's Function ◽  
Normal State ◽  
Coherence Length ◽  
Einstein Condensation ◽  
Two Dimensional ◽  
Bose Einstein Condensation ◽  
Bose Einstein

We investigate the fluctuation contribution to the specific heat of a two-dimensional superconductor with a non-Fermi normal state described by a Anderson Green's function [Formula: see text]. The specific heat corrections contain a term proportional to [Formula: see text] and another logarithmic one. We define a coherence length as function of the non-Fermi paramter α, which shows that a crossover study between BCS and Bose-Einstein condensation is possible by varying the non-Fermi parameter α.

BCS-BEC CROSSOVER WITHOUT APPEAL TO SCATTERING LENGTH THEORY

2014 ◽  
Vol 28 (08) ◽  
pp. 1450054 ◽  
Author(s):  
G. P. MALIK
Keyword(s):  
Interaction Parameter ◽  
Scattering Length ◽  
Critical Values ◽  
Einstein Condensation ◽  
Cooper Pairs ◽  
Bose Einstein Condensation ◽  
The Subject ◽  
Bose Einstein

BCS-BEC (an acronym formed from Bardeen, Cooper, Schrieffer and Bose–Einstein condensation) crossover physics has customarily been addressed in the framework of the scattering length theory (SLT), which requires regularization/renormalization of equations involving infinities. This paper gives a frame by frame picture, as it were, of the crossover scenario without appealing to SLT. While we believe that the intuitive approach followed here will make the subject accessible to a wider readership, we also show that it sheds light on a feature that has not been under the purview of the customary approach: the role of the hole–hole scatterings vis-à-vis the electron–electron scatterings as one goes from the BCS to the BEC end. More importantly, we show that there are critical values of the concentration (n)and the interaction parameter (λ) at which the condensation of Cooper pairs takes place; this is a finding in contrast with the view that such pairs are automatically condensed.

scholarly journals Temporal coherence of spatially indirect excitons across Bose–Einstein condensation: the role of free carriers

2018 ◽  
Vol 20 (7) ◽  
pp. 073049 ◽  
Author(s):  
Romain Anankine ◽  
Suzanne Dang ◽  
Mussie Beian ◽  
Edmond Cambril ◽  
Carmen Gomez Carbonell ◽  
...  
Keyword(s):  
Temporal Coherence ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Free Carriers ◽  
Indirect Excitons ◽  
Bose Einstein

Role of attractive interactions on Bose-Einstein condensation

1996 ◽  
Vol 54 (1) ◽  
pp. 661-664 ◽  
Author(s):  
R. J. Dodd ◽  
Mark Edwards ◽  
C. J. Williams ◽  
C. W. Clark ◽  
M. J. Holland ◽  
...  
Keyword(s):  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Bose Einstein

scholarly journals Bose–Einstein condensation in one-dimensional optical lattices: Bogoliubov’s approximation and beyond

2016 ◽  
Vol 94 (7) ◽  
pp. 697-703
Author(s):  
Mohamed K. Al-Sugheir ◽  
Mufeed A. Awawdeh ◽  
Humam B. Ghassib ◽  
Emad Alhami
Keyword(s):  
Lattice Points ◽  
Effect Of Temperature ◽  
Einstein Condensation ◽  
Condensate Fraction ◽  
Number Density ◽  
One Dimensional ◽  
Bose Einstein Condensation ◽  
Different Temperatures ◽  
Bose Einstein

Bose–Einstein condensation in a finite one-dimensional atomic Bose gas trapped in an optical lattice is studied within Bogoliubov’s approximation and then beyond this approximation, within the static fluctuation approximation. A Bose–Hubbard model is used to construct the Hamiltonian of the system. The effect of the potential strength on the condensate fraction is explored at different temperatures; so is the effect of temperature on this fraction at different potential strengths. The role of the number of lattice points (the size effect) at constant number density (the filling factor) is examined; so is the effect of the number density on the condensate fraction. The results obtained are compared to other published results wherever possible.

Sign in / Sign up

Export Citation Format

Share Document