20 research outputs found
Statistical mechanical description of liquid systems in electric field
We formulate the statistical mechanical description of liquid systems for
both polarizable and polar systems in an electric field in the
-ensemble, which is the pendant to the thermodynamic description in
terms of the free energy at constant potential. The contribution of the
electric field to the configurational integral in
the -ensemble is given in an exact form as a factor in the
integrand of . We calculate the contribution of the
electric field to the Ornstein-Zernike formula for the scattering function in
the -ensemble. As an application we determine the field induced
shift of the critical temperature for polarizable and polar liquids, and show
that the shift is upward for polarizable liquids and downward for polar
liquids.Comment: 6 page
Universal energy distribution for interfaces in a random field environment
We study the energy distribution function for interfaces in a
random field environment at zero temperature by summing the leading terms in
the perturbation expansion of in powers of the disorder strength,
and by taking into account the non perturbational effects of the disorder using
the functional renormalization group. We have found that the average and the
variance of the energy for one-dimensional interface of length behave as,
, , while the distribution
function of the energy tends for large to the Gumbel distribution of the
extreme value statistics.Comment: 4 pages, 2 figures, revtex4; the distribution function of the total
and the disorder energy is include
Localization transition of random copolymers at interfaces
We consider adsorption of random copolymer chains onto an interface within
the model of Garel et al. Europhysics Letters 8, 9 (1989). By using the replica
method the adsorption of the copolymer at the interface is mapped onto the
problem of finding the ground state of a quantum mechanical Hamiltonian. To
study this ground state we introduce a novel variational principle for the
Green's function, which generalizes the well-known Rayleigh-Ritz method of
Quantum Mechanics to nonstationary states. Minimization with an appropriate
trial Green's function enables us to find the phase diagram for the
localization-delocalization transition for an ideal random copolymer at the
interface.Comment: 5 page