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Related papers: Effect of Disorder in BCS-BEC Crossover

200 papers

We study the superconducting proximity effect in inhomogeneous systems in which a disordered or quasicrystalline normal-state wire is connected to a BCS superconductor. We self-consistently compute the local superconducting order parameters…

Superconductivity · Physics 2020-11-04 Gautam Rai , Stephan Haas , Anuradha Jagannathan

We investigate here the BCS BEC crossover in relativistic systems using a variational construct for the ground state and the minimization of the thermodynamic potential. This is first studied in a four fermion point interaction model and…

High Energy Physics - Phenomenology · Physics 2009-01-16 Bhaswar Chatterjee , Hiranmaya Mishra , Amruta Mishra

We present a truly canonical theory of superconductivity in ultrasmall metallic grains by variationally optimizing fixed-N projected BCS wave-functions, which yields the first full description of the entire crossover from the bulk BCS…

Superconductivity · Physics 2009-10-31 Fabian Braun , Jan von Delft

We present a field-theory description of ultracold bosonic atoms in presence of a disordered external potential. By means of functional integration techniques, we aim to investigate and review the interplay between disordered energy…

Quantum Gases · Physics 2019-06-18 Alberto Cappellaro , Luca Salasnich

We study how a randomness of either boson or fermion site energies affects the superconducting phase of the boson fermion model. We find that, contrary to what is expected for s-wave superconductors, the non-magnetic disorder is detrimental…

Superconductivity · Physics 2009-11-07 T. Domanski , K. I Wysokinski

We study the evolution of dynamic properties of the BCS/BEC (Bose-Einstein Condensate) crossover in a relativistic superfluid as well as its thermodynamics. We put particular focus on the change in the soft mode dynamics throughout the…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. Abuki

Collisionless damping of a condensate of cold Fermi atoms, whose scattering is controlled by a Feshbach resonance, is explored throughout the BCS and BEC regimes when small perturbations on its phase and amplitude modes are turned on to…

Quantum Gases · Physics 2012-05-07 Chi-Yong Lin , Da-Shin Lee , Ray J. Rivers

We present a theoretical study of the ground state of the BCS-BEC crossover in dilute two-dimensional Fermi gases. While the mean-field theory provides a simple and analytical equation of state, the pressure is equal to that of a…

Quantum Gases · Physics 2015-08-17 Lianyi He , Haifeng Lv , Gaoqing Cao , Hui Hu , Xia-Ji Liu

We revise the problem of the density of states in disordered superconductors. Randomness of local sample characteristics translates to the quenched spatial inhomogeneity of the spectral gap, smearing the BCS coherence peak. We show that…

Superconductivity · Physics 2013-10-16 M. A. Skvortsov , M. V. Feigel'man

We study a gas of fermions undergoing a wide resonance s-wave BCS-BEC crossover, in the BEC regime at zero temperature. We calculate the chemical potential and the speed of sound of this Bose-condensed gas, as well as the condensate…

Superconductivity · Physics 2009-11-11 J. Levinsen , V. Gurarie

In two-dimensional Dirac semimetals, Cooper pairing instability occurs only when the attractive interaction strength $|u|$ is larger than some critical value $|u_{c}|$ because the density of states vanishes at Dirac points. Disorders…

Superconductivity · Physics 2017-02-17 Jing Wang , Peng-Lu Zhao , Jing-Rong Wang , Guo-Zhu Liu

We investigate the thermodynamics and signatures of a polariton condensate over a range of densities, using a model of microcavity polaritons with internal structure. We determine a phase diagram for this system including fluctuation…

Strongly Correlated Electrons · Physics 2007-05-23 Jonathan Keeling , P. R. Eastham , M. H. Szymanska , P. B. Littlewood

I consider relaxation of the pairing amplitude in a disordered Bardeen-Cooper-Schrieffer (BCS) superconductor in the absence of the two-particle collisions. My main assumption is that nonmagnetic and magnetic disorder scattering rates are…

Superconductivity · Physics 2024-03-11 Maxim Dzero

We model fermions with an attractive interaction in an optical lattice with a single-band Hubbard model away from half-filling with on-site attraction $U$ and nearest neighbor hopping $t$. Our goal is to understand the crossover from BCS…

Superconductivity · Physics 2011-07-20 Parag Ghosh

The Binder cumulant (BC) has been widely used for locating the phase transition point accurately in systems with thermal noise. In systems with quenched disorder, the BC may show subtle finite-size effects due to large sample-to-sample…

Statistical Mechanics · Physics 2007-05-23 Hyunsuk Hong , Hyunggyu Park , Lei-Han Tang

We investigate the quench dynamics of strongly coupled superconductors within the time-dependent Gutzwiller approximation from the BCS to the BEC regime and evaluate the out-of-equilibrium transient spectral density and optical conductivity…

Superconductivity · Physics 2020-10-14 G. Seibold , J. Lorenzana

We analyze the phase diagram of superfluidity for two-species fermion mixtures from the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) limit as a function of scattering parameter, population imbalance and mass…

Superconductivity · Physics 2009-11-13 M. Iskin , C. A. R. Sa de Melo

The subject of BCS - Bose Einstein condensation (BEC) crossover is particularly exciting because of its realization in ultracold Fermi gases and its possible relevance to high temperature superconductors. In the paper we review that body of…

Other Condensed Matter · Physics 2015-05-13 K. Levin , Qijin Chen , Chih-Chun Chien , Yan He

Using the coarse-grain averaged hydrodynamic approach, we calculate all low energy transverse excitation spectrum of a rotating Fermi superfluid containing vortex lattices for all regimes along the BEC-BCS crossover. In the fast rotating…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Tarun Kanti Ghosh , Kazushige Machida

By an exact numerical calculation of the BCS pair wavefunction and the density correlation functions both between atoms in the same and in different spin states, we extract the spatial large distance behavior of the respective functions.…

Quantum Gases · Physics 2020-04-01 J. C. Obeso-Jureidini , V. Romero-Rochin