# Quantum Switch for the Quantum Internet: Noiseless Communications through Noisy Channels

## TL;DR

This paper explores how a quantum switch can enhance quantum teleportation by enabling noiseless communication through noisy channels, leveraging indefinite causal order to improve reliability in quantum networks.

## Contribution

It provides a theoretical analysis demonstrating the performance benefits of using a quantum switch in quantum teleportation, a novel approach in quantum communication engineering.

## Key findings

- Quantum switch increases the probability of noiseless teleportation with higher channel noise.
- Employing a quantum switch can make quantum communication more robust against noise.
- The analysis shows counter-intuitive benefits of indefinite causal order in quantum channels.

## Abstract

Counter-intuitively, quantum mechanics enables quantum particles to propagate simultaneously among multiple space-time trajectories. Hence, a quantum information carrier can travel through different communication channels in a quantum superposition of different orders, so that the relative time-order of the communication channels becomes indefinite. This is realized by utilizing a quantum device known as quantum switch. In this paper, we investigate, from a communication-engineering perspective, the use of the quantum switch within the quantum teleportation process, one of the key functionalities of the Quantum Internet. Specifically, a theoretical analysis is conducted to quantify the performance gain that can be achieved by employing a quantum switch for the entanglement distribution process within the quantum teleportation with respect to the case of absence of quantum switch. This analysis reveals that, by utilizing the quantum switch, the quantum teleportation is heralded as a noiseless communication process with a probability that, remarkably and counter-intuitively, increases with the noise levels affecting the communication channels considered in the indefinite-order time combination.