Dynamical Properties of the t-J Model

Yasuhiro Saiga, Shinji Watanabe, Mitsuhiro Arikawa +5 more

Jiang Xun

The atomic dynamical properties in the multiphoton Jaynes-Cummings model are studied by the numerical method.The frequency of the field varying with time in the sinusoidal forms has been considered.Te atomic dynamical properties are influenced by the frequency parameters and the field varying with time.

Riccardo Aiudi, Raffaella Burioni, A. Vezzani

We investigate critical equilibrium and out of equilibrium properties of a ferromagnetic Ising model in one and two dimensions in the presence of long-range interactions, ${J}_{ij}\ensuremath{\propto}{r}^{\ensuremath{-}(d+\ensuremath{\sigma})}$. We implement a local dynamics on a dynamical L\'evy lattice, that correctly reproduces the static critical exponents known in the literature, as a function of the interaction parameter $\ensuremath{\sigma}$. Due to its locality the algorithm can be applied to investigate dynamical properties, of both discrete and continuous long-range models. We consider the relaxation time at the critical temperature and we measure the dynamical exponent $z$ as a function of the decay parameter $\ensuremath{\sigma}$, highlighting that the onset of the short-range regime for the dynamical critical properties appears to occur at a value of $\ensuremath{\sigma}$ which differs from the equilibrium one.

Yung‐Chung Chen, Hanks Chien

Andrea Giansanti, Daniele Moroni, Alessandro Campa

The $α$-XY model generalizes, through the introduction of a power-law decaying potential, a well studied mean-field hamiltonian model with attractive long-range interactions. In the $α$-model, the interaction between classical rotators on a lattice is gauged by the exponent $α$ in the couplings decaying as $r^α$, where $r$ are distances between sites. We review and comment here a few recent results on the static and dynamic properties of the $α$-model. We discuss the appropriate $α$ dependent rescalings that map the canonical thermodynamics of the $α$-model into that of the mean field model. We also show that the chaotic properties of the model, studied as a function of $α$ display an universal behaviour.