Perturbative Treatment of Quantum to Classical Transition in Chiral Molecules: Dilute Phase vs. Condensed Phase

TL;DR

This paper studies how chiral molecules transition between quantum and classical behaviors in different environments, revealing that dilute and condensed phases influence racemization and quantum Zeno effects differently through perturbation theory.

Contribution

It introduces a perturbative approach to analyze chiral molecule dynamics in dilute and condensed phases with different spectral densities, highlighting environment-dependent effects.

Findings

Dilute phase leads to racemization of chiral molecules.

Condensed phase induces the quantum Zeno effect, inhibiting racemization.

Short-time dynamics are sensitive to initial states and coupling strength in the dilute phase.

Abstract

We examine the dynamics of chiral states of chiral molecules with high tunneling rates in dilute and condensed phases in the context of time-dependent perturbation theory. The chiral molecule is 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 the dilute phase) and in water (as the 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 chiral molecule and to the strength of the coupling between the molecule and the environment.