Resilience of Quantum Teleportation Fidelity for Bipartite Mixed States near Schwarzschild and Dilaton Black Holes

TL;DR

This paper studies how quantum teleportation fidelity behaves near black holes, showing it can remain above classical limits for certain states despite entanglement degradation caused by spacetime curvature.

Contribution

It analyzes the robustness of quantum teleportation fidelity for bipartite mixed states near Schwarzschild and Dilaton black holes, considering relativistic effects and different initial states.

Findings

Teleportation fidelity remains above 2/3 for W-class states near black holes.

GHZ-derived states do not maintain fidelity above the classical threshold.

Entanglement degrades but teleportation can still be feasible with suitable initial states.

Abstract

We investigate the robustness of quantum teleportation in the presence of strong gravitational fields by analysing bipartite mixed states derived from tripartite GHZ and W-class states near black hole event horizons. Considering a scenario where two observers approach the horizon of either a Schwarzschild or a Garfinkle Horowitz Strominger (GHS) Dilaton black hole while a third remains in flat space, we quantify the teleportation fidelity of the resulting bipartite channels after tracing out one party. Through the quantization of Dirac fields and Bogoliubov transformations, we compute the teleportation fidelity under the influence of Hawking radiation and spacetime curvature. Our results show that while entanglement degrades, teleportation fidelity remains above the classical threshold of $f>\frac{2}{3}$ for channels derived from W-class states, but not for GHZ-derived states. This indicates that quantum teleportation can remain feasible near black holes provided the initial entangled state retains useful bipartite entanglement.