Decoherence of Macroscopic Quantum Systems in Dilute Condensed Phases: Chiral Molecules

We examine the generic dynamics of classical states of a macroscopic quantum system in dilute and condensed phases in the context of time-dependent perturbation theory. We apply our approach to chiral molecules with high tunneling rates. Such molecules are effectively described by an asymmetric double-well potential, whose asymmetry is a measure of chiral interactions. The dilute and condensed phases are conjointly described by a collection of harmonic oscillators but respectively with temperature-dependent sub-ohmic and temperature-independent ohmic spectral densities. We examine our method quantitatively by applying the dynamics to isotopic ammonia molecule, NHDT, in an inert background gas (as a dilute phase) and in water (as a condensed phase). As different spectral densities implies, the extension of the dynamics from the dilute phase to the condensed phase is not trivial. While the dynamics in the dilute phase leads to racemization, the chiral interactions in the condensed phase induce the quantum Zeno effect. Moreover, contrary to the condensed phase, the short-time dynamics in the dilute phase is sensitive to the initial state of the molecule and to the strength of molecule-environment coupling.