# Quantum Shannon theory with superpositions of trajectories

## TL;DR

This paper extends quantum Shannon theory by quantising both the information and its trajectories, revealing novel phenomena when information propagates through multiple quantum channels simultaneously.

## Contribution

It introduces a second level of quantisation for information trajectories, expanding the scope of quantum Shannon theory beyond classical paths.

## Key findings

- Demonstrates counterintuitive phenomena with superpositions of transmission lines
- Shows quantum superpositions of trajectories affect information capacity
- Provides examples illustrating the new quantum effects

## Abstract

Shannon's theory of information was built on the assumption that the information carriers were classical systems. Its quantum counterpart, quantum Shannon theory, explores the new possibilities arising when the information carriers are quantum systems. Traditionally, quantum Shannon theory has focussed on scenarios where the internal state of the information carriers is quantum, while their trajectory is classical. Here we propose a second level of quantisation where both the information and its propagation in spacetime is treated quantum mechanically. The framework is illustrated with a number of examples, showcasing some of the counterintuitive phenomena taking place when information travels simultaneously through multiple transmission lines.