Confinement and single-electron tunneling in Schottky-gated, laterally squeezed double-barrier quantum-well heterostructures

The conductance of laterally confined double-barrier quantum-well resonant-tunneling heterostructures is investigated. The confinement is provided by a Schottky gate and can be varied in a continuous way, giving direct proof of the quantum-size effect. Data for dots with nominal diameters in the submicrometer range are reported. Possible evidence for a modulation of the Coulomb blockade by quantum confinement is presented.