Electron conduction characteristics of split-gate structures fabricated on pseudomorphic GaAs-In<sub>x</sub>Ga<sub>1-x</sub>As-AlGaAs heterostructures
D R Mace; M P Grimshaw; D A Ritchie; C J B Ford; M Pepper; G A C Jones; D R Mace; Cavendish Lab., Cambridge Univ., UK; M P Grimshaw; Cavendish Lab., Cambridge Univ., UK; D A Ritchie; Cavendish Lab., Cambridge Univ., UK; C J B Ford; Cavendish Lab., Cambridge Univ., UK; M Pepper; Cavendish Lab., Cambridge Univ., UK; G A C Jones; Cavendish Lab., Cambridge Univ., UK
Журнал:
Journal of Physics: Condensed Matter
Дата:
1993-04-19
Аннотация:
Sub-micron split-gate structures have been fabricated on three pseudomorphic GaAs-In<sub>x</sub>Ga<sub>1-x</sub>As-AlGaAs quantum well structures, with indium fraction, x of 0.04, 0.10, and 0.14. The conductance characteristic of the device on the x=0.04 material showed clear plateaux due to the quantization of ballistic conduction in one dimension. Devices fabricated from the x=0.10 and x=0.14 material did not show plateaux, but exhibited a complex structure that varied quantitatively between nominally identical devices. This structure is thought to be due to both the random nature of the In<sub>x</sub>Ga<sub>1-x</sub>As alloy, and the roughness of the In<sub>x</sub>Ga<sub>1-x</sub>As interfaces. The spatial variation of the potential between the arms of the split gate due to these effects was probed by applying a differential voltage between the two gates.
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