Trade-off coding for universal qudit cloners motivated by the Unruh effect

Understand

A "triple trade-off" capacity region of a noisy quantum channel provides a more complete description of its capabilities than does a single capacity formula.

• However, few full descriptions of a channel's ability have been given due to the difficult nature of the calculation of such regions---it may demand an optimization of information-theoretic quantities over an infinite number of channel uses.
• This work analyzes the d-dimensional Unruh channel, a noisy quantum channel which emerges in relativistic quantum information theory.
• We show that this channel belongs to the class of quantum channels whose capacity region requires an optimization over a single channel use, and as such is tractable.