One-dimensional electronic systems in ultrafine mesa-etched single and multiple quantum well wires

Ultrafine mesa-etched structures with lateral geometrical dimensions of 250 to 550 nm have been prepared in modulation-doped AlGaAs/GaAs heterostructures and multiple quantum well systems. From magnetotransport measurements at low temperatures (T=2.2 K) on these single and multiple quantum well wire structures we find that the lateral carrier confinement leads to the formation of one-dimensional electronic subbands of typically 2 meV energy separation. The width of the electron channel is smaller than the geometrical width, indicating a lateral depletion length of about 100 to 150 nm at the mesa edge.