5. Conclusion

This overview does not claim to describe the entire field covered by the application of semiconductor heterostructures in nanoelectronics and nanophotonics. Nonetheless, the avenues outlined show the degree of complexity that has been achieved thanks to the ever-improving quality of manufacturing techniques. The race for miniaturization continues in one or more spatial directions, each time accompanied by a reduction in the number of electrons and/or photons involved in the device's active principle. We're moving towards single-electron electronics, and dreaming of manufacturing a single-photon source... Artificial structures will undoubtedly enable progress in this field. This will certainly imply profound (r)evolutions in circuit architectures, a field still relatively unexplored, even if we are beginning to find, in the literature, new proposals for digital circuits ("cellular quantum...