Vacancy diffusion in the triangular-lattice dimer model

Monwhea Jeng, Mark John Bowick, Werner Krauth, Jennifer M Schwarz, Xiangjun Xing

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We study vacancy diffusion on the classical triangular-lattice dimer model, subject to the kinetic constraint that dimers can only translate, but not rotate. A single vacancy, i.e., a monomer, in an otherwise fully packed lattice, is always localized in a treelike structure. The distribution of tree sizes is asymptotically exponential and has an average of 8.16±0.01 sites. A connected pair of monomers has a finite probability of being delocalized. When delocalized, the diffusion of monomers is anomalous: x 2 ∝ tβ, with β=0.46±0.06. We also find that the same exponent β governs diffusion of clusters of three or four monomers, as well as the diffusion of dimers at finite but low monomer densities. We argue that coordinated motion of monomer pairs is the basic mechanism allowing large-scale transport at low monomer densities. We further identify a "swap-tunneling" mechanism for diffusion of monomer pairs, where a subtle interplay between swap moves (translations of dimers transverse to their axes) and glide moves (translations of dimers parallel to their axes) plays an essential role.

Original languageEnglish (US)
Article number021112
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume78
Issue number2
DOIs
StatePublished - Aug 12 2008

Fingerprint

Triangular Lattice
Vacancy
Dimer
monomers
dimers
Swap
Glide
Model
Anomalous
Transverse
Kinetics
Exponent
Motion
exponents
kinetics

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Condensed Matter Physics
  • Statistical and Nonlinear Physics
  • Mathematical Physics

Cite this

Vacancy diffusion in the triangular-lattice dimer model. / Jeng, Monwhea; Bowick, Mark John; Krauth, Werner; Schwarz, Jennifer M; Xing, Xiangjun.

In: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, Vol. 78, No. 2, 021112, 12.08.2008.

Research output: Contribution to journalArticle

Jeng, Monwhea ; Bowick, Mark John ; Krauth, Werner ; Schwarz, Jennifer M ; Xing, Xiangjun. / Vacancy diffusion in the triangular-lattice dimer model. In: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. 2008 ; Vol. 78, No. 2.
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