Short-imaginary-time quantum critical dynamics in the J-Q3 spin chain

摘要

We study the short-imaginary-time quantum critical dynamics (SITQCD) in the J-Q_3 spin chain, which hosts a quasi-long-range-order phase to a valence bond solid transition. By using the scaling form of the SITQCD with a saturated ordered phase, we are able to locate the critical point at q_c = 0.170(14). We also obtain the critical initial slip exponent θ = -0.507(3) and the static exponent β/v = 0.498(2). More strikingly, we find that the scaling dimension of the initial order parameter x_0 is close to zero, which suggests that the initial order parameter is a marginal operator. As a result, there is no initial increase behavior of the order parameter in the short-imaginary-time relaxation process for this model, which is very different from the relaxation dynamics in the Ising-type phase transitions. Our numerical results are realized by the projector quantum Monte Carlo algorithm.