Classicality in Quantum Mechanics: model for pointer states and decoherence

TL;DR

This paper investigates how classical states emerge in quantum systems through interaction models, highlighting the stability of certain privileged states that resemble classical pointer states due to environmental interactions.

Contribution

It introduces a perturbative interaction model explaining the emergence of stable classical-like states in quantum systems, extending previous decoherence theories.

Findings

Privileged states remain stable due to environmental orthogonality

Random phase mechanism supports classicality emergence

Subsystem separability is maintained in privileged states

Abstract

We have studied the emergence of classical states in the perturbative interaction model. The states which interact with many other degrees of freedom, such as the center of mass of a macro-object, play important role. Although the random phase mechanism is effective as same as Zurek's strong correlation model, there are enormous states, each of which independently developes due to the orthogonality of the environmental states. In these privileged states, the subsystem picture with the separability is stable.