Quantum theory of polarimetry: From quantum operations to Mueller matrices

TL;DR

This paper develops a quantum framework for polarimetry, linking quantum channels to classical Mueller matrices, enabling new insights into quantum effects in polarization measurements and improved discrimination methods.

Contribution

It introduces quantum channels corresponding to all Mueller matrices, bridging classical polarimetry with quantum theory and enabling enhanced analysis of polarization transformations.

Findings

Quantum channels correspond to all Mueller matrices.

New method to distinguish depolarizing from nondepolarizing matrices.

Quantum properties influence classical polarization measurements.

Abstract

Quantum descriptions of polarization show the rich degrees of freedom underlying classical light. While changes in polarization of light are well-described classically, a full quantum description of polarimetry, which characterizes substances by their effects on incident light's polarization, is lacking. We provide sets of quantum channels that underlie classical polarimetry and thus correspond to arbitrary Mueller matrices. This allows us to inspect how the quantum properties of light change in a classical polarimetry experiment, and to investigate the extra flexibility that quantum states have during such transformations. Moreover, our quantum channels imply a new method for discriminating between depolarizing and nondepolarizing Mueller matrices, which has been the subject of much research. This theory can now be taken advantage of to improve estimation strategies in classical polarimetry and to further explore the boundaries between classical and quantum polarization.