When: July 12, 14:00
Where: Skoltech, MR-426 (TROC-3, Blue building)
Scale-up quantum technologies with solid-state single-photon sources
Dr. Niccolo Somaschi
Development of optical quantum technologies have been hold back for several years by the absence of true quantum light emitters and inefficient performances of detecting devices. Together with linear optical elements, in form of waveguides and phase-shifters as part of integrated circuit, sources and detectors represent the ubiquitous hardware for the realization of an optical quantum computer.
Although, reaching computational complexity towards a quantum advantage and beyond, presently, it is still out of target. Despite in the past few years we assisted to the large deployment of near-unity efficient detectors in combination with low-loss and high speed integrated circuitry, both commercially available, the technological bottleneck is still represented by the currently implemented sources of quantum light. Standard lasers in combination with non-linear processes (ex. Spontaneous Parametric Down Conversion – SPDC) represent the most implemented systems but their unescapable probabilistic mechanism for generating single-photons ultimately limits the emitted photon rate and puts clear barriers on the scalability of quantum protocols. On the contrary, deterministic emitters of quantum states of light, so called “photon guns”, represent the ideal solution for several quantum technologies and for this reason have been subject of an intensive technological effort.
Quandela fabricates and commercialises efficient sources of pure single-photons based on a fully integrated solid-state technology developed in the past 15 years at the “Centre of Nanosciences and Nanotechnologies” (CNRS/UPSud) in the group of Prof. Pascale Senellart. By placing a single semiconductor quantum-dot in an optical cavity in a fully controlled way, we obtain single-photon sources with single-photon purity and indistinguishability over 95%, and brightness exceeding by a factor 20 the one of currently implemented laser-based sources [1-2]. Such performances permit to reduce computing time turning days into minutes  and at the same time allow the efficient generation of large N-photon entangled states for implementation of both computation and communications protocols with complexity levels much larger than the one currently achievable.
In this talk I will give a brief overview about the technology at the core of Quandela and discuss how these devices can be used as building-blocks for the realisation of optical quantum computers and quantum networks.
Dr. Niccolo Somaschi graduated from the University Milano-Bicocca (Italy) in 2009 and received a Ph.D degree in physics from the University of Southampton (UK) in 2013. He then moved to France to work as post-doctorate researcher in the field of quantum photonics at the Centre of Nanoscience and Nanotechnology, a research laboratory part of the national research institute CNRS. During these years he contributed to the developments of solid-state single-photon sources, bringing the performance of such devices to the current state-of-the-art. Following this work, in 2017 he co-founded Quandela, a company providing the most efficient commercial sources of quantum light to boost the research in quantum optics, to allow the emergence of further innovations in the field of quantum photonics and scale up quantum technologies outside the academic world. He currently holds the position of CTO at Quandela, managing a team of 6 people and following several R&D programs, partnerships and customers at the international level.