  Spinless fermions on a honeycomb lattice provide a minimal realization of
lattice Dirac fermions. Repulsive interactions between nearest neighbors drive
a quantum phase transition from a Dirac semimetal to a charge-density-wave
state through a fermionic quantum critical point, where the coupling of Ising
order parameter to the Dirac fermions at low energy drastically affects the
quantum critical behavior. Encouraged by a recently discovery of absence of the
fermion sign problem in this model, we study the fermionic quantum critical
point using the continuous time quantum Monte Carlo method with worm sampling
technique. We estimate the transition point $V/t= 1.356(1)$ with the critical
exponents $\nu =0.80(3)$ and $\eta =0.302(7)$. Compatible results for the
transition point are also obtained with infinite projected entangled-pair
states.
