Multiple negative transconductance and differential conductance in a bipolar transistor by sequential quenching of resonant tunneling

Abstract
The operation of the first multistate bipolar transistor is reported. Multiple peaks are obtained in the collector current‐voltage characteristics by sequentially quenching resonant tunneling through a series of double barriers placed in the emitter. GaInAs npn devices with two AlInAs/GaInAs double barriers exhibit two peaks in the direct and transfer characteristics, with peak‐to‐valley ratios in the latter as high as 4:1 and 20:1 at 300 and 77 K, respectively. The intrinsically multistate operation of this new transistor opens up exciting opportunities for digital and analog circuits with greatly reduced complexity and multiple valued logic.