Trion states and quantum criticality of attractive SU(3) Dirac fermions

We perform the projector quantum Monte Carlo (QMC) simulation to study the trion formation and quantum phase transition in the half filled attractive SU(3) Hubbard model on a honeycomb lattice. With increasing attractive Hubbard interaction, our simulations demonstrate a continuous quantum phase transition from the semimetal to charge-density wave (CDW) at the critical coupling Uc/t = -1.52(2 ). The critical exponents & nu; = 0.82(3) and & eta; = 0.58(4) determined by the QMC simulation remarkably disagree with those of the N = 3 chiral Ising universality class suggested by the effective Gross-Neveu-Yukawa (GNY) theory, but coincide with the N = 1 chiral Ising universality class. In the CDW phase, we show that on-site and off-site trions coexist and the off-site trion forms a local bond state. Our work not only illustrates the formation of off-site trions in two-dimensional Hubbard model but also raises doubts about the extent of applicability of GNY model on attractive SU(3) Dirac fermions.

Automated summary

We used projector quantum Monte Carlo (QMC) simulation to investigate trion formation and quantum phase transition in an attractive SU(3) Hubbard model on a honeycomb lattice. Our simulations revealed a continuous quantum phase transition from semimetal to charge-density wave (CDW) as the attractive Hubbard interaction increased, with a critical coupling Uc/t = -1.52(2). Surprisingly, the critical exponents & nu; = 0.82(3) and & eta; = 0.58(4) determined by the QMC simulation did not agree with those predicted by the N = 3 chiral Ising universality class but rather matched the N = 1 chiral Ising universality class. Furthermore, we found that in the CDW phase, both on-site and off-site trions coexist, with the off-site trion forming a local bond state. This study not only provides insights into the formation of off-site trions in a two-dimensional Hubbard model but also questions the applicability of the GNY model to attractive SU(3) Dirac fermions.