
Thermal phase transition of generalized Heisenberg models for SU(N) spins on square and honeycomb latticesThermal phase transition of generalized Heisenberg models for SU(N) spins on square and honeycomb latticesAA11187113 
"/Suzuki, Takafumi/"Suzuki, Takafumi ,
"/Harada, Kenji/"Harada, Kenji ,
"/Matsuo, Haruhiko/"Matsuo, Haruhiko ,
"/Todo, Synge/"Todo, Synge ,
"/Kawashima, Naoki/"Kawashima, Naoki
91
(
9
)
20150316 , American Physical Society
ISSN:10980121
NCID:AA11187113
Description
We investigate thermal phase transitions to a valencebond solid phase in SU(N) Heisenberg models with four or sixbody interactions on a square or honeycomb lattice, respectively. In both cases, a thermal phase transition occurs that is accompanied by rotational symmetry breaking of the lattice. We perform quantum Monte Carlo calculations in order to clarify the critical properties of the models. The estimated critical exponents indicate that the universality classes of the square and honeycomblattice cases are identical to those of the classical XY model with a Z[4] symmetrybreaking field and the threestate Potts model, respectively. In the squarelattice case, the thermal exponent, ν, monotonically increases as the system approaches the quantum critical point, while the values of the critical exponents, η and γ/ν, remain constant. From a finitesize scaling analysis, we find that the system exhibits weak universality, because the Z[4] symmetrybreaking field is always marginal. In contrast, ν in the honeycomblattice case exhibits a constant value, even in the vicinity of the quantum critical point, because the Z[3] field remains relevant in the SU(3) and SU(4) cases.
FullText
http://repository.kulib.kyotou.ac.jp/dspace/bitstream/2433/198602/1/PhysRevB.91.094414.pdf