Quantumness and Entanglement Witnesses

TL;DR

This paper compares the concepts of quantumness and entanglement witnesses, demonstrating that all entanglement witnesses are also quantumness witnesses, and provides explicit examples of such witnesses in relevant physical scenarios.

Contribution

It establishes the relationship between quantumness and entanglement witnesses and constructs explicit examples, clarifying their connection in quantum physics.

Findings

All entanglement witnesses are also quantumness witnesses.

Explicit construction of witnesses in physical examples.

Clarification of the relationship between quantumness and entanglement.

Abstract

We analyze the recently introduced notion of quantumness witness and compare it to that of entanglement witness. We show that any entanglement witness is also a quantumness witness. We then consider some physically relevant examples and explicitly construct some witnesses.