Scaling in the fan of an unconventional quantum critical point

We present results of extensive finite-temperature quantum Monte Carlo simulations on a SU(2) symmetric S=1/2 quantum antiferromagnet with four-spin interaction. Our simulations, which are free of the sign problem and carried out on lattices containing in excess of 1.6×104 spins, indicate that the four-spin interaction destroys the Néel order at an unconventional z=1 quantum critical point, producing a valence-bond solid paramagnet. Our results are consistent with the "deconfined quantum criticality" scenario.