Condensed Matter Theory

Abstract:

The effect of scattering on the information transfer rate for cell phones and wireless microwave communication devices was analyzed. The antennas in the array measures the relative phase and amplitude of the signal arriving from the particular source and then transmits with the same relative amplitude but with opposite phase. It is found that the scattering instead of decreasing the efficiency, increases the information transfer rate for wireless communication devices.

Abstract:

We describe a lattice Boltzmann algorithm to simulate liquid crystal hydrodynamics. The equations of motion are written in terms of a tensor order parameter. This allows both the isotropic and the nematic phases to be considered. Backflow effects and the hydrodynamics of topological defects are naturally included in the simulations, as are non-Newtonian flow properties such as shear thinning and shear banding. © 2001 The American Physical Society.

Abstract:

We prove that the distribution functions of magnetization and spin glass order parameter coincide on the Nishimori line in the phase diagram of the +/-J Ising model in any dimension. This implies absence of replica symmetry breaking because the distribution function of magnetization consists only of two delta functions, suggesting the same simple structure for the distribution of the spin glass order parameter. It then follows that the mixed (glassy) phase, where ferromagnetic order coexists with a complex phase space structure, should lie below the Nishimori line if it exists at all. We also argue that the AT line that marks the onset of RSB with a continous distribution of the spin glass order parameter (again, if it exists) would start with an infinite slope from the multicritical point where paramagnetic, ferromagnetic and spin glass phases merge.