Dissipative quantum dynamics in 2D: Anisotropic dissipation and selective bond breaking in surface photochemistry

The dissipative quantum dynamics of a model system, Oz at a Pt(lll) surface , has been solved in two dimensions using a stochastic wave packet approach and parallel-computing techniques. it is found that, upon excitation, the dissipation anisotropy creates nonequilibrium and anisotropic energy storag e between different reaction channels. The latter determines decisively the short-time reaction dynamics and, in particular. the branching ratio betwe en desorption and dissociation, in agreement with recent experimental findi ngs.