English

Mott-insulator to commensurate-solid transition in a 4He layer on \alpha-graphyne: Pseudo-spin symmetry breaking under a particle-induced pseudo-magnetic field

Materials Science 2013-08-13 v1 Other Condensed Matter

Abstract

Path-integral Monte Carlo calculations were performed to study the adsorption of 4^4He atoms on α\alpha-graphyne. We find that one 4^4He atom can be embedded onto the in-plane center of each hexagon of the graphyne. In the first 4^4He layer above the 4^4He-embedded graphyne surface, a Mott insulating state was observed at the areal density of 0.0706 \AA2^{-2} with three 4^4He atoms occupying each hexagonal cell while the helium atoms form a commensurate triangular solid at a density of 0.0941 \AA2^{-2}. Here we show that the Ising pseudo-spin symmetry introduced for two degenerate configurations of three 4^4He atoms in a hexagonal cell can be broken by additional 4^4He atoms placed at the hexagon vertices and the Mott-insulator to commensurate-solid transition is a transition from a nonmagnetic spin liquid of frustrated antiferromagnets to a spin-aligned ferromagnet under a particle-induced pseudo-magnetic field.

Keywords

Cite

@article{arxiv.1308.2556,
  title  = {Mott-insulator to commensurate-solid transition in a 4He layer on \alpha-graphyne: Pseudo-spin symmetry breaking under a particle-induced pseudo-magnetic field},
  author = {Yongkyung Kwon and Hyeondeok Shin and Hoonkyung Lee},
  journal= {arXiv preprint arXiv:1308.2556},
  year   = {2013}
}

Comments

5 pages, 4 figures, submitted to Physical Review Letters