UNRUH EFFECT ON QUANTUM TELEPORTATION AND ENTANGLEMENT: IMPLICATIONS ON BLACK HOLE INFORMATION

Akio Hosoya

Xian-Hui Ge, Sang Pyo Kim

We study the properties of quantum entanglement and teleportation in the background of stationary and rotating curved spacetimes with extra dimensions. We show that a maximally entangled Bell state in an inertial frame becomes less entangled in curved space due to the well-known Hawking–Unruh effect. The degree of entanglement is found to be degraded with the increase in the extra dimensions. For a finite black hole surface gravity, the observer may choose a higher frequency mode to keep high level entanglement. The fidelity of quantum teleportation is also reduced because of the Hawking–Unruh effect. We discuss the fidelity as a function of extra dimensions, mode frequency, black hole mass and black hole angular momentum parameter for both bosonic and fermionic resources.

Soroush Haseli

Bradler, Kamil, Christoph Adami

We study the properties of the quantum information transmission channel that emerges from the quantum dynamics of particles interacting with a black hole horizon. We calculate the quantum channel capacity in two limiting cases where a single-letter capacity is known to exist: the limit of perfectly reflecting and perfectly absorbing black holes. We find that the perfectly reflecting black hole channel is closely related to the Unruh channel and that its capacity is non-vanishing, allowing for the perfect reconstruction of quantum information outside of the black hole horizon. We also find that the complementary channel (transmitting entanglement behind the horizon) is entanglement-breaking in this case, with vanishing capacity. We then calculate the quantum capacity of the black hole channel in the limit of a perfectly absorbing black hole and find that this capacity vanishes, while the capacity of the complementary channel is non-vanishing instead. Rather than inviting a new crisis for quantum physics, this finding instead is in accordance with the quantum no-cloning theorem, because it guarantees that there are no space-like surfaces that contain both the sender's quantum state and the receiver's reconstructed quantum state.

Zehua Tian, Jieci Wang, Jiliang Jing

Sevda Mirzaei, Amin Rezaei Akbarieh

Abstract In this paper, we describe the properties of quantum entanglement and teleportation between Alice and Bob who is freely falling toward the Schwarzschild black hole. To this aim, in the flat Minkowski spacetime before a black hole is formed, Alice and Bob share a two-mode entangled coherent state (ECS) generated by Kerr medium and the beam splitter. We will show that the degree of entanglement decreases with increasing the radius of black hole r. Moreover, the fidelity of quantum teleportation via ECS, as a quantum channel, is also reduced because of the Hawking-Unruh effect.