Open Conference Systems, StatPhys 27 Main Conference

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Modulated phases in a driven lattice gas model
Maxim Lavrentovich, Ronald Dickman, Royce Zia

##manager.scheduler.building##: Edificio San Jose
##manager.scheduler.room##: Aula Magna
Date: 2019-07-12 03:15 PM – 03:30 PM
Last modified: 2019-06-10

Abstract


We consider the driven Widom-Rowlinson lattice gas (DWRLG) in which two particle species, A and B, hop into neighboring vacant sites with a bias in the drive direction. The particles have excluded volumes and a repulsion between unlike species, implemented by forbidding A and B nearest neighbors. This repulsive interaction drives a phase separation between As and Bs at high density. Recent simulations of the DWRLG [Phys. Rev. E. 97, 062126 (2018)] demonstrate that in the phase-separated phase, the drive induces the formation of a smectic-like stripe order perpendicular to the drive.  Signatures of this stripe order persist in the disordered (low-density) phase, with characteristic peaks in the structure factor of the gas, reminiscent of a microemulsion phase.   We derive a field theory associated with the DWRLG via the Doi-Peliti formalism, and show using perturbation theory how such a stripe ordering may arise in a continuum theory for the model.  The simulations also demonstrate an interesting linear cusp in the structure factor at small wavevector along the drive direction, which we argue may be captured by loop corrections in our field theory.