Consistent scaling exponents at the deconfined quantum-critical point

Understand

We report a quantum Monte Carlo study of the phase transition between antiferromagnetic and valence-bond solid ground states in the square-lattice $S=1/2$ $J$-$Q$ model.

• The critical correlation function of the $Q$ terms gives a scaling dimension corresponding to the value $\nu = 0.455 \pm 0.002$ of the correlation-length exponent.
• This value agrees with previous (less precise) results from conventional methods, e.g., finite-size scaling of the near-critical order parameters.
• We also study the $Q$-derivatives of the Binder cumulants of the order parameters for $L^2$ lattices with $L$ up to $448$.