arXiv subjects

E. Carlon

Publications and source records attributed to E. Carlon.

22 records · Page 2Linked to original sources

arXiv2003

Magnetophoresis in the Rubinstein-Duke model

We consider the magnetophoresis problem within the Rubinstein-Duke model, i.e. a reptating polymer pulled by a constant field applied to a single repton at the edge of a chain. Extensive density matrix renormalization calculations are presented of the drift velocity and the profile of the chain for various strengths of the driving field and chain lengths. We show that the velocities and the average densities of stored length are well described by simple interpolating crossover formulae, derived under the assumption that the difference between the drift and curvilinear velocities vanishes for sufficiently long chains. The profiles, which describe the average shape of the reptating chain, also show interesting features as some non-monotonic behavior of the links densities for sufficiently strong pulling fields. We develop a description in which a distinction is made between links entering at the pulled head and at the unpulled tail. At weak fields the separation between the head zone and the tail zone meanders through the whole chain, while the probability of finding it close to the edges drops off. At strong fields the tail zone is confined to a small region close to the unpulled edge of the polymer.

cond-mat.stat-mech↗

arXiv2002

Inter-strand distance distribution of DNA near melting

The distance distribution between complementary base pairs of the two strands of a DNA molecule is studied near the melting transition. Scaling arguments are presented for a generalized Poland-Scheraga type model which includes self-avoiding interactions. At the transition temperature and for a large distance r the distribution decays as 1/r^κwith κ=1+(c-2)/ ν. Here νis the self-avoiding walk correlation length exponent and c is the exponent associated with the entropy of an open loop in the chain. Results for the distribution function just below the melting point are also presented. Numerical simulations which fully take into account the self-avoiding interactions are in good agreement with the scaling approach.

cond-mat.stat-mech↗

arXiv2001

Universal phase boundary shifts for corner wetting and filling

The phase boundaries for corner wetting (filling) in square and diagonal lattice Ising models are exactly determined and show a universal shift relative to wetting near the bulk criticality. More generally, scaling theory predicts that the filling phase boundary shift for wedges and cones is determined by a universal scaling function $R_d(ψ)$ depending only on the opening angle $2ψ$. $R_d(ψ)$ is determined exactly in $d=2$ and approximately in higher dimensions using non-classical local functional and mean-field theory. Detailed numerical transfer matrix studies of the the magnetisation profile in finite-size Ising squares support the conjectured connection between filling and the strong-fluctuation regime of wetting.

cond-mat.stat-mech↗

arXiv1999

Interfacial adsorption in two-dimensional Potts models

The interfacial adsorption W at the first-order transition in two-dimensional q-state Potts models is studied. In particular, findings of Monte Carlo simulations and of density-matrix renormalization group calculations, at q= 16, are consistent with the analytic result, obtained in the Hamiltonian limit at large values of q, that W \propto t^{-1/3} on approach to the bulk critical temperature T_c, t=|T_c-T|/T_c. In addition, the numerical findings allow to estimate corrections to scaling. Our study supports and specifies a previous conclusion by Bricmont and Lebowitz based on low-temperature expansions.

cond-mat↗