Speaker's Brief Introduction：Armando Rastelli is Professor of Semiconductor Physics and Head of the Semiconductor Physics Division at the Johannes Keppler University Linz, since 06/2012. Before joining JKU, he received his PhD degree in Physics in 2003 from the University of Pavia, Italy. During his PhD he was research assistant at the ETH Zürich, Switzerland, and Marie-Curie-Fellow at the Technical University of Tampere, Finland. From 2003 to 2007 he was first PostDoc and then group leader at the Max-Planck-Institute of Stuttgart (MPI-FKF) and, till 2012 at the Leibniz Institute of Dresden (IIN-IFW), Germany.
His group has been developing new methods to fabricate, study, and control semiconductor quantum dots as high-quality sources of quantum light. At present, the main research goal lies in the efficient and high-rate generation and characterization of entangled photonic states and their use for quantum communication and quantum optics experiments.
In 2019 he was elected corresponding member of the Austrian Academy of Sciences. He is also board member of the Austrian Physical Society (ÖPG) and board member of the Austrian Microelectronics Society (GME).
Abstract:
Emerging photonic quantum technologies require the development of high-performance sources of quantum light. Among different platforms, self-assembled GaAs quantum dots (QDs) in AlGaAs matrix [1] have demonstrated excellent performance both as quantum emitters [2] as well as hosts of electron and nuclear spins with long coherence times [3]. The most established method to produce GaAs QDs relies on the Al-droplet etching epitaxy [1]. Under optimized conditions, the QDs have high in-plane symmetry, good ensemble homogeneity, high oscillator strengths, and high optical quality, especially when embedded in charge-tunable diode structures [2-5]. These properties make them particularly suited for the generation of polarization-entangled photon pairs. To make sure the QDs fulfil
simultaneously criteria of maximal brightness, desired emission wavelength and charge state, it is necessary to integrate them into photonic devices, which ideally should display a high degree of tunability.
References:
[1] C. Heyn, et al., Appl. Phys. Lett. 94, 183113 (2009). Y. Huo et al., Appl. Phys. Lett. 102, 152105 (2013). M. Gurioli, Z. Wang, A. Rastelli, T. Kuroda, S. Sanguinetti, Nature Materials, 18(8), 799–810 (2019). S. F. C. da Silva, G. Undeutsch, B. Lehner, S. Manna, T. M. Krieger, M. Reindl, C. Schimpf, R. Trotta and A. Rastelli, Appl. Phys. Lett. 119, 120502 (2021).
[2] L. Zhai, et al., Nat. Nanotechnol. 17, 829–833 (2022).
[3] L. Zaporski, et al., Nat. Nanotechnol. 18, 257–263 (2023).
[4] C. Schimpf, et al. Advanced Photonics, 3, 065001 (2021).
[5] G. Undeutsch, et al. Nano Letters, 25(17), 7121–7127 (2025).
[6] I. Brytavskyi, et al., https://arxiv.org/abs/2607.11494
[7] M. Aigner, et al., https://arxiv.org/abs/2608.24409