Nano-Phononics and Nano-Photonics with Semiconductor Nanowires

If the capability to control photons and electrons in crystals has brought to an astonishing level of knowledge as well as to extraordinary technological achievements, the manipulation of phonons is still quite unexplored, despite it holds the promise of a quantum-mechanical control of heat transport [1]. The quantum-mechanical behavior of phonons may also enable the realization of coherent phonon transport via phonon engineering. Nanostructures, such as semiconducting nanowires (NWs), are an ideal platform for Nano-phononics, since they offer the possibility to modify to a large extent the phonon properties by enabling the formation of different kinds of heterostructures and superlattices. I will discuss advanced methods based on Raman spectroscopy to determine the crystalline and phononic properties of nanoscale heterostructures [2] and show how the number of phonons modes can be decided à la carte by tuning the superlattice period in NWs [3].
In the second part of the talk, I will focus on the optical properties of III-V NWs and their dependence on crystal structure useful for band-gap engineering [4]. I will also introduce the open challenges in Nano-photonics and present the new research line I am starting in Basel, aimed at developing a new approach for embedding site-controlled quantum dots in NWs. Dots-in-NWs with high brightness and high light extraction efficiency can be the solid-state building blocks of novel photonic crystals and photonic circuits, and open new paths in quantum communication.
 
References
[1] M. Maldovan, Nature 503, 209, (2013).
[2] C. Fasolato, M. De Luca, D. Djomani, et al., “Crystalline, Phononic, and Electronic Properties of Heterostructured Polytypic Ge Nanowires by Raman Spectroscopy”. Nano Letters 18, 7075 (2018).
[3] M. De Luca, C. Fasolato, M. A. Verheijen, et al., “Phononic properties à la carte in twinning superlattice GaP nanowires”, under review (2019).
[4] M. De Luca and A. Polimeni, “Electronic properties of wurtzite-phase InP nanowires determined by optical and magneto-optical spectroscopy”, Applied Physics Reviews 4, 041102 (2017).
Bio: Dr. Marta De Luca has just started an Ambizione grant funded by the Swiss National Science Foundation in the Physics Department of the University of Basel (Switzerland). Previously, she was post-doc for three years in the same university in the Nanophononics group, where she has investigated phonon engineering in low-dimensional systems. Dr. De Luca graduated in Physics in 2011 at Sapienza University of Rome (Italy) and obtained the Ph.D. in Materials Science in 2014 from the same university. During the Ph.D. she investigated the optical and magneto-optical properties of semiconductor nanowires, for which she was awarded the “Piero Brovetto Prize” by the Italian Society of Physics.