Numerical estimate of the Kardar-Parisi-Zhang universality class in (2+1) dimensions

We study the restricted solid on solid model for surface growth in spatial dimension d = 2 by means of a multisurface coding technique that allows one to produce a large number of samples in the stationary regime in a reasonable computational time. Thanks to (i) a careful finite-size scaling analysis of the critical exponents and (ii) the accurate estimate of the first three moments of the height fluctuations, we can quantify the wandering exponent with unprecedented precision: χd=2 = 0.3869(4). This figure is incompatible with the long-standing conjecture due to Kim and Koesterlitz that hypothesized χd=2 = 2/5.