Title 



Quantum effects in a freestanding graphene lattice : pathintegral against classical Monte Carlo simulations
 
Author 



 
Abstract 



In order to study quantum effects in a twodimensional crystal lattice of a freestanding monolayer graphene, we have performed both pathintegral Monte Carlo (PIMC) and classical Monte Carlo (MC) simulations for temperatures up to 2000 K. The REBO potential is used for the interatomic interaction. The total energy, interatomic distance, rootmeansquare displacement of the atom vibrations, and the free energy of the graphene layer are calculated. The obtained lattice vibrational energy per atom from the classical MC simulation is very close to the energy of a threedimensional harmonic oscillator 3k(B)T. The PIMC simulation shows that quantum effects due to zeropoint vibrations are significant for temperatures T < 1000 K. The quantum contribution to the lattice vibrational energy becomes larger than that of the classical lattice for T < 400 K. The lattice expansion due to the zeropoint motion causes an increase of 0.53% in the lattice parameter. A minimum in the lattice parameter appears at T similar or equal to 500 K. Quantum effects on the atomic vibration amplitude of the graphene lattice and its free energy are investigated.   
Language 



English
 
Source (journal) 



Physical review : B : condensed matter and materials physics.  Lancaster, Pa, 1998  2015  
Publication 



Lancaster, Pa : 2015
 
ISSN 



10980121 [print]
1550235X [online]
 
Volume/pages 



92:19(2015), 6 p.
 
Article Reference 



195416
 
ISI 



000368095400004
 
Medium 



Eonly publicatie
 
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