Novel heterostructure device for electronic pulse-mode neural circuits

A new approach to the hardware implementation of artificial, electronic pulse-mode neural circuits is proposed and demonstrated based on the use of a novel heterostructure device that exhibits an S-type current-voltage characteristic. The new device consists of a multi-period quantum well structure with heavily doped n+ GaAs quantum wells and undoped AlGaAs barriers between an n+ GaAs cathode and p+ GaAs anode. When operated with an RC load, the device switches periodically between a low-conductance off state and a high-conductance on state generating a pulse-mode output. The operation is analogous to that of the axon hillock or trigger zone of the neuron, exhibiting a threshold behavior and a nonlinear dependence of the pulse frequency on the input voltage (mean membrane potential). Low-voltage and room-temperature operation are shown to be feasible.<
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