Our Goals
Nanostructures, such as 2D materials or nanowires, have revolutionized the field of semiconductors, making it possible, among others, to transform indirect bandgap materials to direct bandgap materials, or making it possible for a crystal to grow in a crystal structure that does not exist in bulk. However, in the Nano-spectroscopy group we are not happy to work just with nanostructures: we create nanostructures inside the nanostructures. In our vision the nanostructures are scaffolds embedding smaller quantum structures (quantum dots, point defects that emit single photons, quantum rings, quantum wells, etc.) with diverse dimensionalities (0D, 1D, and 2D).
We work in close collaboration with several growth laboratories providing nanostructures, and we functionalize them by several methods, such as hydrogen or helium irradiation, laser heating, thermal annealing, nanoscale patterning etc. to achieve the desired properties.Working at the boundaries between fundamental physics and technological applications, our goal is to achieve new functionalities or explore new physical effects.
Advances in Optics and Photonics 13 (2021): 242.
For example, in nanowire lasers, by embedding quantum confined structures as active gain media it is possible to enhance the gain and lower lasing threshold. Moreover, by embedding quantum dots in nanowires for quantum photonic applications based on single photon emitters, it can be possible to obtain a higher photon extraction than in standard self-assembled dots embedded in a 3D matrix, owing to the possibility to design the nanowire to act as a waveguide with a photon out-coupler. This makes quantum dots in nanowires the ideal building block of quantum photonic circuits.
Furthermore, by embedding quantum rings in quantum wells, one can unveil the topological phase of charge carriers, by controlling the appearance of magnetic states expected due to the circular symmetry of the carrier wavefunction (Aharonov-Bohm effect).