arXiv subjects

Deniz Ertas

Publications and source records attributed to Deniz Ertas.

21 records · Page 2Linked to original sources

arXiv1994

Nonequilibrium Dynamics of Fluctuating Lines

These notes are for the proceedings of the NATO Advanced Study Insitutue on "Scale Invariance, Interfaces, and Non--Equilibrium Dynamics", held at the Isaac Newton Institute, 20--30 June 1994. The four lectures address a number of issues related to dynamic fluctuations of lines in non-equilibrium circumstances. The first two are devoted to the critical behavior of contact lines and flux lines depinning from impurities. It is emphasized that anisotropies in the medium lead to different universality classes. The importance of nonlinearities for moving lines are discussed in the context of flux lines and polymers in the last two lectures. A dynamic form birefringence is predicted for drifting polymers.

cond-mat↗

arXiv1994

Anisotropic Scaling in Depinning of a Flux Line

We study the depinning of a flux line by analytical and numerical methods applied to a phenomenological equation of motion. Transverse fluctuations do not influence the critical behavior of the longitudinal component, justifying ``planar approximations". In an isotropic medium, longitudinal fluctuations have a roughness exponent $ζ_\parallel=1$, and relax with a dynamic exponent $z_\parallel\approx4/3$; transverse fluctuations are suppressed ($ζ_\perp=1/2<ζ_\parallel$), and relax more slowly, with $z_\perp=z_\parallel+1$. Anisotropy in the depinning threshold, or orientational dependence of force-force correlations, lead to new universality classes.

cond-mat↗

arXiv1994

Critical Dynamics of Contact Line Depinning

The depinning of a contact line is studied as a dynamical critical phenomenon by a functional renormalization group technique. In $D=2-ε$ interface dimensions, the roughness exponent is $ζ=ε/3$ to all orders in perturbation theory. Thus, $ζ=1/3$ for the contact line, equal to the Imry-Ma estimate of Huse for the equilibrium roughness. The dynamical exponent is $z=1-2ε/9+O(ε^2)<1$, resulting in unusual dynamical properties. In particular, a characteristic distortion length of the contact line depinning from a strong defect is predicted to initially increase faster than linearly in time. Some experiments are suggested to probe such dynamics.

cond-mat↗