Low-temperature dynamics of the 2D spin-1/2 Heisenberg antiferromagnet: A quantum Monte Carlo study

We used a combination of the quantum Monte Carlo technique and the maximum entropy method to calculate the dynamic structure factor of the quantum Heisenberg antiferromagnet. The dynamics is governed by renormalized damped spin waves and we calculate their frequencies and linewidths. The computed spin-wave dispersion is in quantitative agreement with inelastic-neutron-scattering experiments on ${\mathrm{La}}_2$ ${\mathrm{CuO}}_4$. The low-energy sector exhibits scaling behavior with the characteristic frequency scale, which is inversely proportional to the correlation length.