We perform the projector quantum Monte Carlo simulation of the half-filled
attractive SU(3) Hubbard model on a honeycomb lattice, exploring the effects of
SU(3) symmetry on the correlated attractive Dirac fermions. Our simulation
indicates the absence of pairing order in the system and shows a quantum phase
transition from the semimetal to charge density wave (CDW) at the critical
point Uc​=−1.52(2). We demonstrate that this quantum phase transition belongs
to the chiral Ising universality class according to the numerically determined
critical exponents ν=0.82(3) and η=0.58(4). With the increase of
coupling strength, the trion formation is investigated, and the change in
probability of the on-site trion occupancy infers the coexistence of on-site
trionic and off-site trionic CDW states at half-filling.Comment: 12 pages, 12 figure