Observation of zero-bias multi-state behavior in selectively doped two-terminal quantum tunneling devices

Based on a coherent tunneling calculation, we have found multiple self-consistent solutions, even at zero bias, in diodes that combine a tunneling heterostructure with an N/sup -/-N/sup +/-N/sup -/ spacer layer. We have also experimentally observed multiple stable I-V curves in such devices grown in the GaAs/AlAs material system using molecular beam epitaxy. The I-V curves corresponding to the different states remain distinct and separated through zero bias. The device can be repetitively switched between states and maintains memory of its state even under short circuit conditions.<>