title: Microscopic view of a two-dimensional lattice-Gas ising system within the grand canonical ensemble
abstract: A reversible 2D critical transition is observed on the GaAs(001) surface and modeled as a lattice-gas Ising system. Without depositing any material, 2D GaAs islands spontaneously form. The order parameter, four critical exponents, and coupling energies are measured from scanning tunneling microscope images of the microscopic domain structure and correlation functions as a function of temperature and pressure. Unprecedented insight into the domain structure of a 2D Ising system through the critical point and a complete Hamiltonian for modeling the GaAs(001) surface are presented.
authors.affiliation: Department of Physics, The University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors.initials: VP
authors.lastname: LaBella
authors.initials: DW
authors.lastname: Bullock
authors.initials: M
authors.lastname: Anser
authors.initials: Z
authors.lastname: Ding
authors.initials: C
authors.lastname: Emery
authors.initials: L
authors.lastname: Bellaiche
authors.initials: PM
authors.lastname: Thibado