6533b85bfe1ef96bd12bb3ef

RESEARCH PRODUCT

Path-Integral Monte Carlo Simulation for H2 and D2 Adsorbed on Graphite

M. KreerP. Nielaba

subject

Phase transitionMaterials scienceTransition temperatureMoleculeGraphiteSubstrate (electronics)Molecular physicsQuantumScalingPath integral Monte Carlo

description

Molecular layers are very good realizations of two dimensional systems. Hydrogen molecules H 2,HD,D 2 adsorbed on graphite are excellent model systems for investigating the influence of substrate fields and of quantum effects on phase transitions. At a coverage of a complete commensurable layer in the √3 x √3 R30° structure experiments showed an anomalous effect, the system with the lighter H 2 molecules has a higher order-disorder transition temperature compared to the system with the heavier D 2 molecules. By a combination of path integral Monte Carlo and finite size scaling techniques we analyze this effect. In detail we study the order parameter and the cumulants and discuss the impact of the effective “size” of the quantum particles on the location of the critical temperature.

yearjournalcountryeditionlanguage
1997-01-01
https://doi.org/10.1007/978-3-642-60597-0_9