A quantum trajectory description of decoherence

Abstract

A complete theoretical treatment in many problems relevant to physics, chemistry, and biology requires considering the action of the environment over the system of interest. Usually the environment involves a relatively large number of degrees of freedom, this making the problem numerically intractable from a purely quantum-mechanical point of view. To overcome this drawback, a new class of quantum trajectories is proposed. These trajectories, based on the same grounds as Bohmian ones, are solely associated to the system reduced density matrix, since the evolution of the environment degrees of freedom is not considered explicitly. Within this approach, environment effects come into play through a time-dependent damping factor that appears in the system equations of motion. Apart from their evident computational advantage, this type of trajectories also results very insightful to understand the system decoherence. In particular, here we show the usefulness of these trajectories analyzing decoherence effects in interference phenomena, taking as a working model the well-known double-slit experiment. PACS. 03.65.-w Quantum mechanics (general) -03.65.Ta Foundations of quantum mechanics; measurement theory -03.65.Yz Decoherence; open systems; quantum statistical methods -03.75.Dg Atom and neutron interferometry

Understanding interference experiments with polarized light through photon trajectories

“…5(a). It is worth mentioning that the loss of the interference fringes as well as the lack of wiggling features in the trajectories is similar to the behavior found in trajectories for massive particles in the case of decoherence [59,60].…”

What dynamics can be expected for mixed states in two-slit experiments?

“…If only the density matrix in the position representation, ρ(r ′ , r, t), is accessible, after Eq. (10) we may then use [23] rρ(r, t) = m Im ∇ r ′ ρ(r ′ , r, t) ρ(r ′ , r, t)…”

Trajectory description of the quantum–classical transition for wave packet interference

“…During the transition, decoherence occurs and it is the irreversible emergence of classical properties. Quantum trajectories have been employed to analyze the decoherence processes of physical systems [90][91][92][93][94][95], and these studies provide an alternative trajectory description for the quantum-classical transition.…”