95 citations · 450 across the 43 of their papers we have counts for
15 papers · 1 filter
Band filling effects on coherence lengths and penetration depth in the two-orbital negative-U Hubbard model of superconductivity
Grzegorz Litak, Teet Örd, Küllike Rägo +1
The two-orbital superconducting state is modeled by on-site intra-orbital negative-U Hubbard correlations together with inter-orbital pair-transfer interactions. The critical tempe…
Coherence lengths for superconductivity in the two-orbital negative-U Hubbard model
G. Litak, T. Ord, K. Rago +1
We study the peculiarities of coherency in the superconductivity of two-orbital system. The superconducting phase transition is caused here by the on-site intra-orbital attractions…
Magnetic field orientation effect on specific heat in a p-wave superconductor
Grzegorz Litak, Karol I. Wysokinski
The effect of magnetic field on specific heat of a p-wave spin triplet superconductor has been analyzed. To describe superconductivity we used a single band model with various real…
Magnetic field induced rotation of the d-vector in Sr_2RuO_4
J. F. Annett, G. Litak, B. L. Gyorffy +1
The superconductor Sr_2RuO_4 is widely believed to be a spin triplet system with a chiral order parameter analogous to the A phase of superfluid helium-3. The best evidence for thi…
Superconducting Pairing Amplitude and Local Density of States in Presence of Repulsive Centers
Grzegorz Litak, Mariusz Krawiec
We study the properties of superconductor in presence of a finite concentration of repulsive centers. The superconductor is described by the negative Hubbard model while repuls…
Variations of Pairing Potential and Charge Distribution in Presence of a Non-magnetic Impurity
Grzegorz Litak
Using an attractive Hubbard model we examine spatial variations of superconducting order parameter and local charge on a two dimensional lattice. For various band filling we show t…
'Pi State' Induced by Impurities with a Repulsive Interaction
Grzegorz Litak, Mariusz Krawiec
We study the properties of a quantum impurity embedded in a superconducting host. The superconductor is described by the negative U Hubbard model while the impurity introduces a re…
Specific Heat of Disordered Superconductors Induced by Negative Centers
Grzegorz Litak
We show that superconductors with inhomogeneous order parameters can show similar features as anisotropic ones. In this paper we study the low temperature specific heat dependence…
Charge and Phase Fluctuations in Attractive Hubbard Model
Grzegorz Litak
Using the negative U Hubbard model we analyze normal state properties of a superconductor. In this model there exists a characteristic pairing temperature T_P above a superconducti…
Superconductivity Induced by Negative Centers
G. Litak, T. Paiva, R. T. Scalettar +2
We study the effect of random dilution of attraction centers on electron pairing in a generalization of the negative Hubbard model where the interaction , defined on the t…
P-wave Pairing in superconducting Sr2RuO4
G. Litak, J. F. Annett, B. L. Gyorffy +1
Two models for the superconducting state of Sr2RuO4 have been analyzed. In an "orbital model" the in-plane and out of-plane interactions between electrons on neighboring Ru atoms a…
Disorder Induced Fluctuations of the Pairing Parameter in P-Wave Superconductors
G. Litak
We study the effect of site diagonal disorder on the pairing amplitude by a perturbation method. Using an extended Hubbard model with the intersite attraction we analyze fluctuatio…
Effect of Disorder on a D-wave Superconductor
Grzegorz Litak
We apply the Coherent Potential Approximation (CPA) to an extended Hubbard model to describe disordered superconductors with d-wave pairing. We discuss the pair-breaking effect cau…
Superconductivity in Disordered Sr2RuO4
G. Litak, J. F. Annett, B. L. Gyorffy
We discuss the influence of disorder on the critical temperature Tc of a p-wave superconductor. To describe disordered Sr2RuO4 we use the extended Hubbard model with random site en…
Percolation of Superconductivity
G. Litak, B. L. Gyorffy
In case of superconductors whose electrons attract each other only if they are near certain centers, the question arises 'How many such centers are needed to make the ground state…