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The effect of finite size of hadrons on the QCD phase diagram is analyzed using relativistic mean field model for the hadronic phase and the Bag model for the QGP phase. The corrections to the EOS for hadronic phase are incorporated in a…

High Energy Physics - Phenomenology · Physics 2012-10-31 Saeed Uddin , Waseem Bashir , Jan Shabir Ahmad

We investigate the electronic and superconducting properties of a negative-U Hubbard model. For this purpose we evaluate a recently introduced variational theory based on Gutzwiller-correlated BCS wave functions. We find significant…

Strongly Correlated Electrons · Physics 2010-02-17 Joerg Buenemann , Florian Gebhard , Katalin Radnoczi , Patrik Fazekas

We study the shape resonance effect associated with the confined transverse superconducting modes of a cylindrical nanowire in the clean limit. Results of numerical investigations of the Bogoliubov-de Gennes equations show significant…

Superconductivity · Physics 2009-11-11 A. A. Shanenko , M. D. Croitoru

The structure of the electron quantum size levels in spherical nanocrystals is studied in the framework of an eight--band effective mass model at zero and weak magnetic fields. The effect of the nanocrystal surface is modeled through the…

Materials Science · Physics 2009-11-07 A. V. Rodina , Al. L. Efros , A. Yu. Alekseev

This report presents a systematic understanding of the nature behind the unusual behavior of a nanosolid, and a surface as well, in mechanics, thermodynamics, acoustics, optoelectronics, magnetism, dielectrics, atomic diffusivity and…

Materials Science · Physics 2007-05-23 Chang Q Sun

We have studied finite-sized single band models with short range pairing interactions between electrons in presence of diagonal Fibonacci modulation in one dimension. Two models, namely the attractive Hubbard model and the Penson-Kolb…

Strongly Correlated Electrons · Physics 2009-11-11 Sanjay Gupta , Shreekantha Sil , Bibhas Bhattacharyya

Borocarbide superconductors, which are thought to be conventional BCS-type superconductors, are not so conventional in several electronic Raman properties. Anisotropic gap-like features and finite scattering strength below the gap were…

Superconductivity · Physics 2015-06-25 In-Sang Yang , M. V. Klein , T. P. Devereaux , I. R. Fisher , P. C. Canfield

How small superconductors can be? For isolated nanoparticles subject to quantum size effects, P.W. Anderson conjectured in 1959 that superconductivity could only exist when the electronic level spacing $\delta$ is smaller than the…

The combined effect of nonmagnetic and magnetic defects and impurities on critical temperatures of superconductors with different gap anisotropy is studied theoretically within the weak coupling limit of the BCS model. An expression is…

Superconductivity · Physics 2009-10-30 Leonid A. Openov

We discuss recent laboratory experiments with rotating superconductors and show that three so far unexplained experimentally observed effects (anomalous acceleration signals, anomalous gyroscope signals, Cooper pair mass excess) can be…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Clovis Jacinto de Matos , Christian Beck

We compare results of high-resolution magnetic flux (susceptibility) measurements in very weak magnetic field, performed of three classes of superconductors. They reveal astonishing details of the transition to the superconducting state.…

Superconductivity · Physics 2009-11-10 Zdenek Janu , Frantisek Soukup , Rudolf Tichy , Georgy Tsoi , Jan Hadac , Jana Vejpravova

The work is dedicated to the development of the electron-lattice energy exchange theory in metal particles and it dependence of on particle size and electron temperature. We obtained the expressions for the constants of the electron-lattice…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Petro Tomchuk , Yevgen Bilotsky

We make use of a BCS type approach based on the extended Hubbard Hamiltonian to study the superconductor transition and to give a microscopic interpre- tation of the pressure effects on Tc in high temperature superconductors. This novel…

Strongly Correlated Electrons · Physics 2009-10-30 E. V. L. de Mello , C. Acha

The issue of quantum size effects of interactive electron-hole systems in spherical semiconductor quantum dots is put to question. A sharper theoretical approach is suggested based on a new pseudo-potential method. In this new setting,…

Materials Science · Physics 2009-04-13 Baptiste Billaud , Marco Picco , T. T. Truong

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…

Superconductivity · Physics 2008-12-18 Tadafumi Ohsaku

Using four different experimental techniques, we performed comprehensive studies of the bulk superconductive properties of single crystals of the nearly optimally doped $Ba_{1-x}K_xFe_2As_2$ ($T_{c} \approx 36\,K$), a typical representative…

We study finite size effects in a family of systems in which a parameter controls interaction-range. In the long-range regime where the infinite-size free energy is universal, we show that the finite size effects are not universal but…

Statistical Mechanics · Physics 2009-11-11 Shin-itiro Goto , Yoshiyuki Y. Yamaguchi

Based on first-principles calculations we showed that superlattices of periodically repeated junctions of hydrogen saturated silicon nanowire segments having different lengths and diameters form multiple quantum well structures. The band…

Mesoscale and Nanoscale Physics · Physics 2010-12-22 Seymur Cahangirov , Salim Ciraci

The theory of hole superconductivity predicts that in superconductors the charged superfluid is about a million times more rigid than the normal electron fluid. We point out that this physics should give rise to large changes in the bulk…

Superconductivity · Physics 2012-04-24 J. E. Hirsch

The comparison study of high pressure superconducting state of recently synthesized H$_3$S and PH$_3$ compounds are conducted within the framework of the strong-coupling theory. By generalization of the standard Eliashberg equations to…

Superconductivity · Physics 2017-07-05 Artur P. Durajski