2007/01/04 by F. Q. Potiguar, Fabricio Q. Potiguar, Ronald Dickman +1 · 4 citations
Chemistry · Engineering · Physics and Astronomy · #Chemistry #Colloid #Condensed matter physics #Empty lattice approximation #Energy landscape #Lattice (music) #Lattice field theory #Microfluidic and Bio-sensing Technologies #Monte Carlo method #Optical lattice #Particle in a one-dimensional lattice #Physics #Quantum mechanics #Random lasers and scattering media #Theoretical and Computational Physics #Thermodynamics #Yukawa potential #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.76.031103
published in Physical Review E 76(3), 031103 (American Physical Society)
arxiv created 2007/01/04 · openalex publication_date 2007/09/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Motivated by recent studies of colloidal particles in optical-tweezer arrays, we study a two-dimensional model of a colloidal suspension in a periodic potential. The particles tend to stay near potential minima, approximating a lattice gas. The interparticle interaction, a sum of Yukawa terms, features short-range repulsion and attraction at somewhat larger separations, such that two particles cannot occupy the same potential well, but occupation of adjacent cells is energetically favored. Monte Carlo simulation reveals that the equilibrium system exhibits condensation, as in the Ising model or lattice gas with conserved magnetization; the transition appears to be continuous at one-half occupancy. We study the effect of biased hopping, favoring motion along one lattice direction, as might be generated by a steady flow relative to the potential array. This system is found to exhibit features of the driven lattice gas: the interface is oriented along the drive, and appears to be smooth. A weak drive facilitates ordering of the particles into high- and low-density regions, while stronger bias tends to destroy order, and leads to very large energy fluctuations. We also study ordering in a moving periodic potential. Our results suggest possible realizations of equilibrium and driven lattice gases in a colloidal suspension subject to an optical tweezer array.