Pure decoherence in quantum systems

A popular model of decoherence based on the linear coupling to harmonic oscillator heat baths is analysed and shown to be inappropriate in the regime where decoherence dominates over energy dissipation, called pure decoherence regime. The similar mechanism essentially related to the energy conservation implies that, on the contrary to some recent conjectures [21], chaotic environments can be less efficient decoherers than regular ones. Finally, the elastic scattering mechanism is advocated as the simplest source of pure decoherence.