Quantum effect device in which conduction between a plurality of quantum dots or wires is achieved by tunnel transition

摘要

In quantum effect devices using quantum dots, a novel quantum effect device which controls the probability of tunnel transition of electrons among quantum dots to obtain quantum effects such as band gap modulation. i-GaAs layers serving as the quantum dots are formed on an n- AlGaAs substrate and, further, n-AlGaAs layers are formed as electron supply layers on the i-GaAs layers. By this double heterojunction structure, channels are formed in the i-GaAs layers near the two junction surfaces sandwiching the layers. On the other hand, a potential barrier layer comprised of an i-AlGaAs layer with a small barrier height with respect to the quantum dots and an SiO.sub.2 layer with a large barrier height laminated together is formed between the quantum dots. The position of the lamination interface in the potential barrier layer is set to a height enabling the two layers to contact the quantum dots. The magnitude of the electric field applied from the control electrode to the quantum dots is used to select one of the two channels. The band gap changes according to the change of the probability of tunnel transition at this time. If the change in the band gap is, for example, converted to a change in light emission wavelength, a variable wavelength type semiconductor laser device can be constructed.