13-12U
13-12U
UDC:
537.9, 536.764
PACS:
03.75.Hh, 03.75.Lm, 64.70.Tg, 71.35.Lk, 37.10.Jk, 67.85.-d Investigation of spectral features of boson spectrum of two-dimensional optical lattices with graphene-type structures. II. SF-phase
A two-sublattice hard-core boson model is proposed for description of graphene-type systems with a honeycomb lattice. Using the previously obtained results as the base, the energy spectrum and the spectral densities for the superfluid (SF) phase are calculated in the random phase approximation. Comparing to the normal phase, the number of spectrum branches and spectral density bands is doubled in the superfluid one. Rearrangement of the spectrum and the spectral density in the SF-phase at variation of temperature and the difference of sublattice local energies are investigated.
Year:
2013
Pages:
11
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