Advantages and disadvantages of maximally entangled states in dilaton black hole background

TL;DR

This paper studies how quantum entanglement and coherence behave near a dilaton black hole, revealing that non-maximally entangled states can outperform maximally entangled ones in such curved spacetime environments.

Contribution

It demonstrates that in a black hole background, non-maximally entangled states can be more robust than maximally entangled states, challenging conventional assumptions about quantum resources.

Findings

Non-maximally entangled states can have higher entanglement than maximally entangled states near a black hole.

Quantum coherence shows a monotonic increase with initial coherence, enhancing robustness against black hole effects.

The optimal quantum state depends on whether entanglement or coherence is the desired resource.

Abstract

We investigate quantum entanglement and coherence for four classes of Bell-like fermionic states in the vicinity of the event horizon of a Garfinkle-Horowitz-Strominger (GHS) dilaton black hole. Contrary to the common expectation that maximally entangled states always provide superior quantum resources, our results show that their entanglement can be lower than that of suitably chosen non-maximally entangled states in this curved spacetime background. This reveals that non-maximally entangled states may offer operational advantages for entanglement-based tasks under gravitational effects. In contrast, quantum coherence exhibits monotonic behavior: larger initial coherence leads to systematically enhanced robustness against the dilaton induced degradation. These results indicate that the optimal choice of initial quantum states depends sensitively on the specific quantum resource, either quantum entanglement or quantum coherence, required for quantum information processing near a dilaton black hole.