Magnetic communication by polarization helicity modulation using atomic magnetometers.

The radio frequency telecommunication at a kilohertz range through an electrically conductive medium is often impeded by the strong reflection and absorption at the interface. The polarization helicity of the magnetic field can be modulated/demodulated to provide a new communication protocol to potentiality circumvent these issues. Here, a miniature magnetic quantum receiver, capable of simultaneously discriminating the two possible helicities of a magnetic field, is presented. The core physics package constitutes two optically pumped atomic magnetometers. It is shown that a data rate of 500 bits/s with a carrier frequency of 2 kHz can be efficiently demodulated in an unshielded environment, paving a promising route for the future of radio frequency communication through a conductive barrier.