Monte Carlo Study of Symmetric Mass Generation and Fermionic Deconfined Quantum Criticality in a Bilayer Honeycomb Lattice Model

By using the state-of-the-art unbiased determinant quantum Monte Carlo simulation, we observe a direct and continuous transition from symmetric Dirac semi-metal phase to a gapped phase with symmetric mass generation (SMG) in a bilayer honeycomb lattice model. We argue that the direct and continuous transition is a fermionic decomfined quantum critical point (fDQCP). Based on careful finite size scaling, we calculate the critical exponents for the fDQCP. Our study gives a solid example of SMG with fDQCP.