The role of quantum degrees of freedom of relativistic fields in quantum information protocols

TL;DR

This paper investigates how quantum degrees of freedom in relativistic fields influence quantum information protocols, distinguishing regimes where quantum or classical descriptions are appropriate, thus clarifying fundamental differences between classical and quantum field theories.

Contribution

It classifies regimes where quantum degrees of freedom are essential versus when classical approximations suffice in relativistic quantum information tasks.

Findings

Quantum degrees of freedom are necessary for certain relativistic quantum interactions.

Classical approximations are valid in specific regimes of relativistic quantum information.

The results help distinguish fundamental differences between classical and quantum field theories.

Abstract

We analyze the differences between relativistic fields with or without quantum degrees of freedom in relativistic quantum information protocols. We classify the regimes where the existence of quantum degrees of freedom is necessary to explain the phenomenology of interacting quantum systems. We also identify the precise regimes where quantum fields can be well approximated by quantum-controlled classical fields in relativistic quantum information protocols. Our results can be useful to discern which features are fundamentally different in classical and quantum field theory.