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

The dissipative quantum dynamics of a model system, O2 at a Pt(111) 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 storage between different reaction channels. The latter determines decisively the short-time reaction dynamics and, in particular, the branching ratio between desorption and dissociation, in agreement with recent experimental findings.