Engineering quantum structures in nanomaterials: functional properties on demand

Abstract: Engineering complex quantum structures in semiconductors has attracted much interest in the last decade, for these structures encode new functionalities and/or enhance the performances of existing devices. Nanowires (NWs) offer an ideal platform to embed quantum structures, such as quantum dots and quantum disks, because the unique growth environment offered by NWs benefits from a much greater flexibility with respect to conventional planar epitaxial growth. So far, quantum structures in NWs were created by exploiting the possibility to tune the crystal structure and the crystal compositions. I will review the most diffused approaches and the technological applications achieved. I will also present a totally new approach for embedding site-controlled quantum structures in III-V NWs. The pursued route will involve mainly post-growth hydrogen incorporation, thus allowing to achieve different NW properties on demand with no need to change and re-optimize NW growth conditions.

In my research, the optical properties of quantum dots, quantum wires, quantum rings, quantum well tubes, and quantum disks in NWs will be engineered to obtain characteristics functional to develop quantum technologies and investigate fundamental quantum mechanical effects. Quantum rings will be the platform of advanced magneto-optical experiments to probe for the first time in NWs the quantum mechanical optical Aharonov-Bohm effect. Moreover, QDs-in-NWs with high brightness and high light extraction efficiency will be in my research the solid-state building blocks of novel photonic crystals, photonic circuits, and quantum sensing devices with tunable properties. The novel generation of solid-state site-controlled single photon emitters proposed here will open new paths in quantum-information processing.