Notes on teleportation in an expanding space

TL;DR

This paper examines how quantum teleportation fidelity is affected by spacetime curvature and horizon effects in de Sitter space, revealing degradation due to Gibbons-Hawking radiation and cavity entanglement limitations, with potential Planck-scale modifications.

Contribution

It analyzes quantum teleportation in de Sitter space using both free scalar modes and cavity-based qubits, highlighting the effects of spacetime curvature and horizon physics on fidelity.

Findings

Teleportation fidelity decreases due to Gibbons-Hawking effect.

Entanglement in cavities is reduced by spacetime curvature.

Planck-scale physics introduces additional fidelity modifications.

Abstract

We investigate the quantum teleportation between a conformal detector Alice and an inertial detector Bob in de Sitter space in two schemes, (i) one uses free scalar modes and (ii) one utilizes cavity to store qubit. We show that the fidelity of the teleportation is degraded for Bob in both cases. While the fidelity-loss is due to the Gibbons-Hawking effect associated with his cosmological horizon in the scheme (i), the entanglement decreases in the scheme (ii) because the ability to entangle the cavities is reduced by the spacetime curvature. With a cutoff at Planck-scale, comparing with the standard Bunch-Davies choice, we also show that the possible Planckian physics cause extra modifications to the fidelity of the teleportation protocol in both schemes.