SOI single-hole transistors with various sizes have been fabricated by converting an abacus bead wire to an island contacted to the source and the drain through two constrictions. Coulomb blockade and quantum confinement oscillations have been observed in these devices. The energy spectrum in the different regions and the energy levels in the constrictions as a function of the gate voltage have been calculated solving Poisson and Schrodinger equations self-consistently The ground-state energy of the hole in the constrictions is lower than in the island, thereby creating a potential barrier.
Xiaohui Tang, Baie, X., Colinge, J. P., Van de Wiele, F., & Bayot, V. (2000). Quantum effects in SOI single-hole transistors. In Lane, W.A.; Crean, G.M.; McCabe, F.A.; Grunbacher, H.; (ed.), ESSDERC 2000. Proceedings of the 30th European Solid-State DeviceResearch Conference (p. p. 220-223). Frontier group. https://hdl.handle.net/2078.5/224232