Transmission of quantum information through quantum fields

TL;DR

This paper explores how two localized quantum systems can communicate via a scalar quantum field, addressing challenges like no-cloning and entanglement breaking, and presents a protocol with maximal quantum capacity.

Contribution

It introduces a non-perturbative protocol for quantum communication through scalar fields that achieves maximal quantum capacity, considering key physical constraints.

Findings

Protocol achieves maximal quantum capacity

Careful navigation of physical constraints is essential

Scalar field communication differs from electromagnetic field communication

Abstract

We investigate the quantum channel consisting of two localized quantum systems that communicate through a scalar quantum field. We choose a scalar field rather than a tensor or vector field, such as the electromagnetic field, in order to isolate the situation where the qubits are carried by the field amplitudes themselves rather than, for example, by encoding qubits in the polarization of photons. We find that suitable protocols for this type of quantum channel require the careful navigation of several constraints, such as the no-cloning principle, the strong Huygens principle and the tendency of short field-matter couplings to be entanglement breaking. We non-perturbatively construct a protocol for such a quantum channel that possesses maximal quantum capacity.