By Hatim Salih, Jonte R. Hance, Will McCutcheon, Terry Rudolph, John Rarity
Submitted to arXiv on 3 August 2020.
The generalisation of counterfactual communication – where classical information is sent without exchanging particles (exchange-free) – to sending quantum information, poses significant experimental challenges. Here, we show how to directly communicate an arbitrary qubit, not only exchange-free but also without the sender having to implement a quantum object locally, paving the way for a much more feasible future demonstration. More remarkably, we propose an exchange-free protocol that allows one party to directly enact, by means of a suitable program, any computation on a remote second party’s unknown qubit, without any particles travelling between them.