Relativistic quantum teleportation protected by the anti-Unruh effect

This study investigates how the non-inertial motion of a quantum participant (Rob) affects the fidelity of quantum teleportation when sharing an entangled state with an inertial participant (Alice). Specifically, the authors examine whether the anti-Unruh effect—a phenomenon where increasing acceleration can suppress thermal noise—can be harnessed to protect quantum information from the relativistic degradation typically associated with the Unruh effect.

The researchers model the participants using Unruh-DeWitt detectors, which are two-level quantum systems that interact locally with a massive scalar field. Alice and Rob share a maximally entangled Bell state in an inertial frame before Rob begins to accelerate. The authors use a first-order perturbative expansion to calculate the evolution of the detector-field system, accounting for the detector's energy gap, the field's mass, and the acceleration. They then evaluate the concurrence (a measure of entanglement) and the average teleportation fidelity as functions of Rob's acceleration.

The study reveals that the impact of acceleration on quantum information depends heavily on the detector's energy gap. For small energy gaps, entanglement and teleportation fidelity increase monotonically with acceleration due to the dominance of the anti-Unruh effect, which reduces the effective temperature perceived by the detector. For larger energy gaps, the system exhibits a non-monotonic response: initial acceleration causes a loss of fidelity due to the standard Unruh effect, but higher accelerations trigger the anti-Unruh effect, which restores coherence and improves teleportation performance. The authors establish a direct quantitative link between the suppression of detector-field entanglement and the recovery of teleportation fidelity.