Detecting quantum properties in physical systems using proxy witnesses

TL;DR

This paper introduces a method to detect quantum properties in large physical systems using proxy witnesses, enabling identification of features like entanglement and coherence in complex many-body models.

Contribution

It develops general proxy witnesses for various quantum properties applicable to large systems, expanding detection techniques beyond microscopic scales.

Findings

Successfully applied proxy witnesses to quantum Heisenberg models

Demonstrated detection of quantum coherence and entanglement in many-body systems

Provided a framework for practical quantum property detection in large systems

Abstract

In practice, it is quite challenging to detect a quantum property, a microscopic property, in a macroscopic system. In our work, we construct general proxy witnesses of quantum properties to detect their presence in quantum systems and we do so for quantum systems which may possibly be large. In particular, we discuss proxy witnesses for quantum properties like unextendibility, quantum coherence, activation, steerability, and entanglement. We apply these proxy witnesses in some widely considered examples of many-body systems, viz., the quantum Heisenberg models, the quantum J1-J2 model.