Wage bargaining and quality competition

In a standard model of vertical differentiation, wage is assumed to determine the quality. Wage is also subject to bargaining. Increased bargaining power of the worker in the low quality firm reduces quality differential, and increases price competitiveness. The Opposite happens from a similar change in the high quality firm.Wage bargaining; Quality competition

Ground state phase diagram and magnetoconductance of a one-dimensional Hubbard superlattice at half-filling

We have studied a one dimensional Hubbard superlattice with different Coulomb correlations at alternating sites for a half-filled band. Mean field calculations based on the Hartree-Fock approximation together with a real space renormalization group technique were used to study the ground state of the system. The phase diagrams obtained in these approaches agree with each other from the weak to the intermediate coupling regime. The mean field results show very quick convergence with system size. The renormalization group results indicate a spatial modulation of local moments that was identified in some previous work. Also we have studied the magnetoconductance of such superlattices which reveals several interesting points.Comment: 10 pages, 13 figures. to be published in Phys. Rev. B, vol. 75, Issue 23 (tentative

Effect of external electric field on the charge density waves in one dimensional Hubbard superlattices

We have studied the ground state of the one dimensional Hubbard superlattice structures with different unit cell sizes in the presence of electric field. Self consistent Hartree-Fock approximation calculation is done in the weak to intermediate interaction regime. Studying the charge gap at the Fermi level and the charge density structure factor, we get an idea how the charge modulation on the superlattice is governed by the competition between the electronic correlation and the external electric field.Comment: 6 pages, 8 figures. accepted in Journal of Physics: Condensed Matte

Effect of Fibonacci Modulation On Superconductivity

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 model, have been investigated at half-filling at zero temperature by solving the Bogoliubov-de Gennes equations in real space within a mean field approximation. The competition between ``disorder'' and the pairing interaction leads to a suppression of superconductivity (of usual pairs with zero centre-of-mass momenta) in the strong-coupling limit while an enhancement of the pairing correlation is observed in the weak-coupling regime for both the models. However, the dissimilarity of the pairing mechanisms in these two models brings about notable difference in the results. The extent to which the bond ordered wave and the $\eta$-paired (of pairs with centre-of-mass momenta = $\pi$) phases of the Penson-Kolb model are affected by the disorder has also been studied in the present calculation. Some finite size effects are also identified.Comment: 14 pages, 13 figure

Wage bargaining and quality competition

In a standard model of vertical differentiation, wage is assumed to determine the quality. Wage is also subject to bargaining. Increased bargaining power of the worker in the low quality firm reduces quality differential, and increases price competitiveness. The Opposite happens from a similar change in the high quality firm

Wage bargaining and quality competition

In a standard model of vertical differentiation, wage is assumed to determine the quality. Wage is also subject to bargaining. Increased bargaining power of the worker in the low quality firm reduces quality differential, and increases price competitiveness. The Opposite happens from a similar change in the high quality firm

Half-filled Hubbard ring with alternating site potentials in a magnetic field

We have studied a Hubbard ring with alternating site potentials for half filling in presence of a magnetic flux. Using a mean field approach we have calculated the conductivity of such a ring at low and high temperatures. The interplay of correlation, the polarizing field and the chemical modulation in the site potentials tune the conductivity in an interesting fashion. In presence of the modulation in the site energy an appreciable variation in the conductance is observed with the change in flux. Finite size effects are also identified and they are found to be quickly disappearing with increasing system size. Sharp changes in the magnetoconductance is found to disappear at higher temperatures.Comment: 15 page