Proposal for a digital converter of analog magnetic signals
  A device which converts analog magnetic signals directly into digital information is proposed. The device concept is based on the monostable-bistable transition logic element, which consists of two resonant tunneling diodes (load and driver) connected in series and employs the monostable to bistable working point transition of the circuit. Using a magnetic resonant tunneling diode as the driver allows to control the resulting working point of the bistable region by an external magnetic field leading either to high or low output voltage of the circuit, effectively realizing what could be called digital magnetoresistance. 
Christian Ertler and Jaroslav Fabian