One-dimensional probability density observed using scanned gate microscopy

Using scanned gate microscopy, we observed transconductance structure relat ing to the transverse electron probability density of a quasi-one-dimension al electron system (Q1DES). The scanned gate created a movable scatterer to modify the transmission probability of the highest transmitted one-dimensi onal (1D) subband. Structure was seen for the first three 1D subbands, in a ddition to transconductance oscillations indicative of 1D ballistic transpo rt. The Q1DES was electrostatically defined from a subsurface two-dimension al electron system created at a GaAs/AlGaAs heterojunction. The Q1DES confi ning potential was modelled as flat in the middle with parabolic walls, and Schrodinger's equation solved numerically using a finite-difference method . Using this model, the experimental Q1DES width and 1D subband energy spac ings were deduced.