BAND-STRUCTURE CALCULATION OF COUPLED-QUANTUM-WIRE SUPERLATTICES AND OPTIMIZATION OF NEGATIVE DIFFERENTIAL-EFFECTS IN PERPENDICULAR TRANSPORT

We have measured the I(V) characteristics in transport of coupled-quan tum-wire superlattices generated from two-dimensional delta-doped supe rlattices using the atomic saw method [1]. We have theoretically analy sed the band structures. The band structure resulting from the restruc turing of space consists of the various mini-bands and mini-gaps accor ding to favoured axes in the Brillouin zone. We propose the optimizati on of these structures changing some parameters like the doping concen tration, the doping width, the periodicity, and/or the width of slippi ng steps so as to get the best uncoupling of the mini-bands responsibl e for negative differential resistance effects in perpendicular transp ort, in spite of the disorder resulting from the wire generation metho d. A comparative study with GaAs/AlAs superlattices is also presented.