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Related papers: The BCS theory amended

200 papers

Condensation energy in a superconductor cannot be precisely defined if mean-field theory fails to hold. This implies that in the case of high temperature superconductors, discussions of quantitative measures of condensation energy must be…

Superconductivity · Physics 2009-11-07 Sudip Chakravarty , Hae-Young Kee , Elihu Abrahams

It is shown that the gap solution and critical transition temperature are significantly enhanced by doping in a recently developed BCS formalism for graphene superconductivity in such a way that positive gap and transition temperature both…

Superconductivity · Physics 2017-09-20 Chenmei Xu , Yisong Yang

In the conventional BCS description of a superconductor the kinetic energy increases in the superconducting state. We describe the observed decrease in kinetic energy by adopting a simple model of electrons whose elastic scattering rate…

Superconductivity · Physics 2009-11-11 Frank Marsiglio

The single-band alpha-model of superconductivity [H. Padamsee, et al., J. Low Temp. Phys. {\bf 12}, 387 (1973)] is a popular model that was adapted from the single-band Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity mainly to…

Superconductivity · Physics 2013-10-15 D. C. Johnston

Superconductivity in the C32 compounds CaAlSi and SrAlSi is investigated by heat capacity (Cp) measurements as well as high-pressure ac-susceptibility experiments. The heat capacity in the superconducting state is well explained by the BCS…

Superconductivity · Physics 2009-11-10 B. Lorenz , J. Cmaidalka , R. L. Meng , C. W. Chu

Superconductors like other solids cannot relax instantaneously from excited states to thermodynamic equilibrium. In this paper, relaxation from thermal excitations is investigated, like after absorption of radiation or, under conductor…

Superconductivity · Physics 2021-11-19 Harald Reiss

According to the BCS model the probability of filling of pair electron states vk2 as a function of kinetic energy is smeared i.e. is not a step function. This means that part of energy of connection through virtual phonons is consumed to…

Superconductivity · Physics 2011-01-04 I. N. Zhilyaev

Influence of the temperature dependent chemical potential on the condensation energy from a ternary Boson-Fermion model of superconductivity is reported, it consist of unbound electrons/holes which are fermions plus two-electron and…

Superconductivity · Physics 2022-09-07 I. Chávez , P. Salas , O. A. Rodríguez , M. A. Solís , M. de Llano

The leading (Gaussian) fluctuation correction to the weak coupling zero temperature BCS superconducting gap equation is computed. We find that the dominant contribution comes from the high energies and momenta (compared to the gap) and…

Strongly Correlated Electrons · Physics 2007-05-23 S. Kos , A. J. Millis , A. I. Larkin

We deal with the gap function and the thermodynamical potential in the BCS-Bogoliubov theory of superconductivity, where the gap function is a function of the temperature $T$ only. We show that the squared gap function is of class $C^2$ on…

Mathematical Physics · Physics 2010-06-07 Shuji Watanabe

We describe the spectral properties of underdoped cuprates as resulting from a momentum-dependent pseudogap in the normal state spectrum. Such a model accounts, within a BCS approach, for the doping dependence of the critical temperature…

Superconductivity · Physics 2009-10-31 L. Benfatto , S. Caprara , C. Di Castro

A General Theory of Superconductivity with points of view differing from those of the BCS Theory is presented in two parts. In the first part, a general equation for the superconductivity is obtained; based on the stable pairing of two…

Superconductivity · Physics 2007-05-23 R. Riera , J. L. Marin

We calculate corrections to the BCS gap equation caused by the interaction of electrons with the collective phase and amplitude modes in the superconducting state. This feedback reduces the BCS gap parameter, $\Delta$, and leaves the…

Condensed Matter · Physics 2009-10-22 Tony Gherghetta , Yoichiro Nambu

A major impediment to solving the problem of high-$T_c$ superconductivity is the ongoing confusion about the magnitude, structure and doping dependence of the superconducting gap, $\Delta_0$, and of the mysterious pseudogap found in…

Superconductivity · Physics 2009-09-01 J. L. Tallon , J. G. Storey

We study quasiparticle energy relaxation at sub-kelvin temperatures by injecting hot electrons into an aluminium island and measuring the energy flux from electrons into phonons both in the superconducting and in the normal state. The data…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 A. V. Timofeev , C. Pascual Garcia , N. B. Kopnin , A. M. Savin , M. Meschke , F. Giazotto , J. P. Pekola

Lately, there has been much interest in high temperature superconductors, and more recently hydrogen-based superconductors. This work offers a simple model which explains the behavior of the superconducting gap based on BCS theory, and…

Superconductivity · Physics 2018-07-04 Daniel Kaplan , Yoseph Imry

Momentum and energy conservation are fundamental tenets of physics, that valid physical theories have to satisfy. In the reversible transformation between superconducting and normal phases in the presence of a magnetic field, the mechanical…

Superconductivity · Physics 2017-01-10 J. E. Hirsch

The superconducting transition in High Temperature Superconductors(HTS) has not been understood. Traditional Bose Einstein Condensation(BEC) theory provides Tc estimates that are many times higher than the experimental values. The proposed…

Superconductivity · Physics 2013-12-05 Vladimir Y. Butko

The superconducting gap - an energy scale tied to the superconducting phenomena-opens on the Fermi surface at the superconducting transition temperature (TC) in conventional BCS superconductors. Quite differently, in underdoped high-TC…

Superconductivity · Physics 2008-01-21 W. S. Lee , I. M. Vishik , K. Tanaka , D. H. Lu , T. Sasagawa , N. Nagaosa , T. P. Devereaux , Z. Hussain , Z. -X. Shen

We review the BCS to Bose Einstein condensation (BEC) crossover scenario which is based on the well known crossover generalization of the BCS ground state wavefunction $\Psi_0$. While this ground state has been summarized extensively in the…

Superconductivity · Physics 2011-09-13 Qijin Chen , Jelena Stajic , Shina Tan , Kathryn Levin