Computer simulation study of the. theta. -point in three dimensions. II. Trails on a simple cubic lattice

Journal Article · Sun Apr 15 04:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.458549· OSTI ID:6830023

Meirovitch, H; Lim, H A ^[1]

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1. Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-4052 (USA)

A self-attracting trail is a walk on a lattice which may intersect itself but two bonds are not allowed to overlap; an interaction energy {epsilon} ({epsilon}{lt}0) is associated with each self-intersection. Using the scanning simulation method, we study the tricritical behavior at the collapse transition of self-attracting trails of {ital N}{le}250 steps on a simple cubic lattice. In the preceding paper (paper I) tricritical self-avoiding walks (SAWs) on the same lattice have been investigated. The tricritical temperature of trails is {minus}{epsilon}/{ital k}{sub B}{ital T}{sub {ital t}}=0.550{plus minus}0.004 (one standard deviation). The results for the radius of gyration, {ital G}, and the end-to-end distance, {ital R}, lead to {nu}{sub {ital t}}=0.515{plus minus}0.003, which is larger than {nu}{sub {ital t}}=1/2, the theoretical prediction for SAWs. The ratio {ital G}{sup 2}/{ital R}{sup 2}=0.1676{plus minus}0.0001 is slightly larger than 1/6=0.1666 ... predicted by theory for SAWs; The results for the partition function at {ital K}{sub {ital t}} lead to {gamma}{sub {ital t}}=1.040{plus minus}0.005 (as compared to the theoretical prediction for SAWs {gamma}{sub {ital t}}=1) and to the growth parameter value {mu}{sub {ital t}}=5.0023{plus minus}0.0020. The crossover exponent, {phi}{sub {ital t}}, is approximately 0.5 as expected for SAWs at tricriticality; this value is significantly smaller than that found for SAWs in paper I. The results of {ital G}, {ital R}, and {ital Z} at {ital K}{sub {ital t}} are found to be inconsistent with logarithmic corrections to scaling. However, we do not think that the above differences between trails and SAWs are sufficient to suggest unequivocally that the two models belong to different universality classes.

• DOE Contract Number: FC05-85ER25000
• OSTI ID: 6830023
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 92:8; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
CHAINS
COMPUTERIZED SIMULATION
CONFIGURATION
CRITICAL TEMPERATURE
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
DATA
DIMENSIONS
FUNCTIONS
INFORMATION
NUMERICAL DATA
PARTITION FUNCTIONS
PHYSICAL PROPERTIES
POLYMERS
SIMULATION
THEORETICAL DATA
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE