A system for transmission of information using a curl-free magnetic vector potential radiation field. The system includes current-carrying apparatus for generating a predominantly curl-free magnetic vector potential field coupled to apparatus for modulating the current applied to the field generating apparatus. Receiving apparatus includes a detector with observable properties that vary with the application of an applied curl-free magnetic vector potential field. Analyzing apparatus for determining the information content of modulation imposed on the curl-free vector potential field is coupled to the detector. The magnetic vector potential field can be established in materials that are not capable of transmitting more common electromagnetic radiation.

The receiver may detect changes of phase of the sine function which determines the Josephson junction current. The distance of the transmitter can be determined from the strength of the received signal. By generating a field of predetermined orientation and using a detector responsive to orientation, the direction of the transmitter may be determined. A rotating field may be used for this.