Yves Lansac

Phase behavior of bent-core molecules.

Recently, a new class of smectic liquid crystal phases characterized by the spontaneous formation of macroscopic chiral domains from achiral bent-core molecules has been discovered. We have carried out Monte Carlo simulations of a minimal hard spherocylinder dimer model to investigate the role of excluded volume interactions in determining the phase behavior of bent-core materials and to probe the molecular origins of polar and chiral symmetry breaking. We present the phase diagram of hard spherocylinder dimers of length-diameter ratio of 5 as a function of pressure or density and dimer opening angle psi. With decreasing psi, a transition from a nonpolar to a polar smectic A phase is observed near psi=167 degrees, and the nematic phase becomes thermodynamically unstable for psi<135 degrees. Free energy calculations indicate that the antipolar smectic A (SmAP(A)) phase is more stable than the polar smectic A phase (SmAP(F)). No chiral smectic or biaxial nematic phases were found.

Entropy-stabilized smectic C phase in a system of zigzag-shaped molecules.

We have carried out Monte Carlo simulations of zig-zag shaped molecules where the the molecules is composed of three rigidly linked hard spherocylinder arranged in a zigzag fashion. By varying zigzag angle we have mapped out the whole phase diagram as a function of pressure, molecular density and zigzag angle

Induced anticlinic ordering and nanophase segregation of bow-shaped molecules in a smectic solvent.

Psi

The elastic depinning transition of vortex lattices in two dimensions

. For

A-site ordering in colossal magnetoresistance manganite La1−xSrxMnO3? Molecular dynamics simulations and quantum mechanics calculations

Psi

Elastic depinning transition for superconductor vortices

between

Coarse-grained simulation of polymer translocation through an artificial nanopore

35^0

Evidence from infrared dichroism, x-ray diffraction, and atomistic computer simulation for a "zigzag" molecular shape in tilted smectic liquid crystal phases.

and

Transition de dépiégeage élastique de vortex supraconducteurs

80^0

Stratification-Driven Symmetry Breaking: The Molecular Origins of SmC Tilt

our model simulation exhibits SmC phase. This is the first conclusive evidence where steric interaction arising out of molecular shape alone induce the occurrence of SmC phase for a wide range of zigzag angle. For smaller