Critical Attractive Spin Systems

Critical Attractive Spin Systems

We study a class of attractive spin systems. We prove that for these processes, the system dies out when the parameters are on the critical surface. We also prove that the supercritical process survives with positive probability in a suuciently thick space-timèslab'.

Critical behavior of random spin systems

We provide a strategy to find in few elementary calculations the critical exponents of the overlaps for dilute spin glasses, in absence of external field. Such a strategy is based on the expansion of a suitably perturbed average of the overlaps, which is used in the formulation of the free energy as the difference between a cavity part and the derivative of the free energy itself, considered as...

Semi-classical Analysis of Spin Systems near Critical Energies

Some Properties of the Spin-Polarized Attractive Hubbard Model

The influence of a Zeeman magnetic field on the superconducting characteristics of the attractive Hubbard model has been investigated. The ground state and temperature phase diagrams have been obtained for a fixed number of particles. Two critical magnetic fields have been found for the first order phase transition from the superconducting (SC) to the normal (NO) state for n 6= 1. For some rang...

Boosting spin-caloritronic effects by attractive correlations in molecular junctions

In nanoscopic systems quantum confinement and interference can lead to an enhancement of thermoelectric properties as compared to conventional bulk materials. For nanostructures, such as molecules or quantum dots coupled to external leads, the thermoelectric figure of merit can reach or even exceed unity. Moreover, in the presence of external magnetic field or when the leads are ferromagnetic, ...