Europhys. Lett.
Volume 73, Number 1, January 2006
Page(s) 76 - 82
Section Condensed matter: structural, mechanical and thermal properties
Published online 02 December 2005
Europhys. Lett., 73 (1), pp. 76-82 (2006)
DOI: 10.1209/epl/i2005-10362-1

Shadow wave function variational calculation of bond orientational order and disclination in liquid and solid $\chem{^{4}He}$

Li Hui1, 2, Li Ying1, Liu Yingcai1, Dong Shunle1 and F. Pederiva2

1  Physics Department, Ocean University of China - Qingdao, PRC
2  Physics Department, University of Trento - I-38050, Povo, Trento, Italy

received 25 April 2005; accepted in final form 2 November 2005
published online 2 December 2005

By means of shadow wave function (SWF), a variational Monte Carlo simulation of 500 particles has been performed to study bond orientational order and disclination defects in liquid and solid $\chem{^{4}He}$. Convincing evidence is presented that this structural order can be interpreted as entanglement and interpenetration of defective icosahedra sharing common vertexes and faces. Thereby, it is demonstrated that a defect as those observed in quantum solid is due to the relatively large-amplitude vibration of $\chem{^{4}He}$ atoms. The matching relation of bonds which is used to form a defective icosahedron has been discussed in this paper.

67.40.-w - Boson degeneracy and superfluidity of $\chem{^{4}He}$.
67.40.Yv - Impurities and other defects.

© EDP Sciences 2005