Physical entanglement in permutation-invariant quantum mechanics

TL;DR

This paper proposes a redefinition of entanglement for indistinguishable quantum systems, especially fermions, emphasizing physical significance over non-separability, building on prior foundational work.

Contribution

It introduces a new entanglement definition for indistinguishable particles, supported by physical principles, extending and refining previous theoretical frameworks.

Findings

Re-defines entanglement for fermions and indistinguishable systems

Establishes physical significance of the new definition

Aligns with principles of distinguishable systems

Abstract

The purpose of this short article is to build on the work of Ghirardi, Marinatto and Weber (Ghirardi, Marinatto & Weber 2002; Ghirardi & Marinatto 2003, 2004, 2005) and Ladyman, Linnebo and Bigaj (2013), in supporting a redefinition of entanglement for "indistinguishable" systems, particularly fermions. According to the proposal, non-separability of the joint state is insufficient for entanglement. The re-definition is justified by its physical significance, as enshrined in three biconditionals whose analogues hold of "distinguishable" systems.