A research group has used fast neutrons <https://www.theregister.com/2021/11/15/wireless_information_transfer_with_fast_neutrons/> as a communication channel, to send legible data between a transmitter and a receiver. Their proof of concept is very low-bandwidth and requires a lot of complicated equipment, but at least it does show (safety issues aside) that it is theoretically possible. The issue with high-energy subatomic particles is, how do you turn them on and off at will -- i.e. modulate the intensity of the beam to convey information? This group used some kind of shutter system (“neutron chopper”) in conjunction with some quantity of radioactive californium-252 as their neutron source. But they mention that someone else has come up with a device that is basically a particle accelerator on a chip, able to produce a stream of neutrons from non-radioactive starting components on demand.