Gaussian quantum steering in multi-event horizon spacetime

TL;DR

This paper investigates how Hawking radiation influences Gaussian quantum steering in Schwarzschild-de Sitter spacetime, revealing that it can both diminish and enhance steering depending on the horizon and temperature conditions.

Contribution

It is the first study to show that Hawking effects can improve quantum steering and to analyze steering asymmetry in multi-horizon spacetime.

Findings

Hawking effect of black hole reduces quantum steering

Hawking effect of universe can enhance quantum steering

Steering asymmetry depends on observer location and temperature

Abstract

We study Gaussian quantum steering in the Schwarzschild-de Sitter (SdS) spacetime that is endowed with both a black hole event horizon (BEH) and a cosmological event horizon (CEH), giving rise to two different Hawking temperatures. It is shown that the Hawking effect of the black hole always reduces the quantum steering, but the Hawking effect of the expanding universe does not always play the same role. For the first time, we find that the Hawking effect can improve quantum steering. We also find that the observer who locates in the BEH has stronger steerability than the observer who locates in CEH. Further, we study the steering asymmetry, and the conditions for two-way, one-way and no-way steering in the SdS spacetime. Finally, we study the Gaussian quantum steering in the scenario of effective equilibrium temperature. We show that quantum steering reduces monotonically with the effective temperature but now increases monotonically with the Hawking temperature of the black hole, which banishes the belief that the Hawking effect can only destroy quantum steering.