Realism-information complementarity in photonic weak measurements

TL;DR

This paper investigates how weak measurements influence the emergence of realistic properties in quantum systems, highlighting the interplay between information gain and back-action in both closed and open two-level systems.

Contribution

It introduces a detailed analysis of the effects of weak measurements on the realism of quantum states, including open systems, advancing understanding of the quantum-classical transition.

Findings

Weak measurements can modify the realism of quantum states.

The study extends to open systems, showing robustness of effects.

Results clarify the role of information and back-action in quantum measurements.

Abstract

The emergence of realistic properties is a key problem in understanding the quantum-to-classical transition. In this respect, measurements represent a way to interface quantum systems with the macroscopic world: these can be driven in the weak regime, where a reduced back-action can be imparted by choosing meter states able to extract different amounts of information. Here we explore the implications of such weak measurement for the variation of realistic properties of two-level quantum systems pre- and post-measurement, and extend our investigations to the case of open systems implementing the measurements.