Exploring the hierarchy of quantum correlations under thermal effects in two gravitational cat states

TL;DR

This paper studies how thermal effects influence different types of quantum correlations, like entanglement and steering, between two gravitational cat states modeled as qubits, revealing their different robustness to temperature.

Contribution

It analyzes the hierarchy of quantum correlations under thermal effects in gravitational cat states, highlighting the persistence of entanglement beyond steerability and the impact of energy differences.

Findings

Concurrence persists even when steerability is lost due to thermal effects.

Temperature affects the degree of quantum correlations between the states.

States become separable when the energy gap is large.

Abstract

In this article, we investigate the hierarchy of quantum correlations between two gravitational cats states (modeled by two qubits). We use concurrence to quantify the entanglement between the two gravitational cat states. Quantum steering is employed to measure the steerabilities. We consider geometric quantum discord to quantify quantum correlations beyond entanglement. We show that the concurrence persists even when steerability is lost under thermal effects. We also show that the temperature influences the degree of quantum correlations between the two gravitational cat states. Besides, when the energy difference between the ground state and the first excited level becomes significant, the states become separable.