Large transconductance oscillations in a single-well vertical Aharonov-Bohm interferometer

Vincenzo Piazza, Fabio Beltram, Werner Wegscheider, Chi-Te Liang, M. Pepper
2000 Physical Review B (Condensed Matter)  
Aharonov-Bohm (AB) interference is reported for the first time in the conductance of a vertical nanostructure based on a single GaAs/AlGaAs quantum well (QW). The two lowest subbands of the well are spatially separated by the Hartree barrier originating from electronic repulsion in the modulation-doped QW and provide AB two-path geometry. Split-gates control the in-plane electronic momentum dispersion. In our system, we have clearly demonstrated AB interference in both electrostatic and
more » ... modes. In the latter case the magnetic field was applied parallel to the QW plane, and perpendicular to the 0.02 um^2 AB loop. In the electrostatic mode of operation the single-QW scheme adopted led to large transconductance oscillations with relative amplitudes exceeding 30 %. The relevance of the present design strategy for the implementation of coherent nanoelectronic devices is underlined.
doi:10.1103/physrevb.62.r10630 fatcat:m27jt7cboje65g6vqfut46hlre