Exciton-polaritons, hybrid light-matter particles, have recently come into the spotlight for their peculiar properties (sizable interaction, small mass, long coherence, etc.) leading to spectacular effects such as phase transitions, superfluidity, bistability, ultra-efficient fourwave-mixing, and quantum blockade. On the other hand, polaritons have also been proposed for different kinds of devices (including optical switches, transistors, low threshold lasers and simulators), with beautiful experiments showing proofs-of-principle. However, it is only recently that polaritons have been operating efficiently at room temperature, giving the promise of a real technological impact in the future. In a recent work, made by some of the theoretical and experimental partners of this proposal, we could demonstrate that such hybrid state of matter, when used for realising artificial neural networks, shows extremely interesting performances in terms of speed and success rate. Given the strong interest in the realisation of hardware-based (not simulated) artificial neural networks, the goal of PolArt is to demonstrate a new way to build artificial intelligence-dedicated circuits using polariton neural networks as optical accelerators. Thanks to this new concept device, complex applications related to neural-like processing, will be efficiently implemented, therefore enabling neuromorphic computation to be done in small devices that cannot rely on remote, large bandwidth connection. This proposal benefits from the contribution of several complementary partners coming from many different research areas (material science, physics, optics, chemistry, genetics) and industrial participants that assure the interdisciplinarity and technological oriented target.

Thirty years ago Dyakonov and Shur opened a new field in solid-state physics and electronics - plasma-wave electronics. They theoretically predicted that: i) in nano-transistors, plasma waves may oscillate at THz frequencies far beyond the devices’ cut-off GHz frequencies, ii) THz radiation can be detected by plasma nonlinearities, and iii) the current flow can lead to the generation of THz radiation. The detection part of the “plasmonics promise” was proven and nowadays THz plasmonic detector arrays are widely used. In the case of emitters, the task turned out to be considerably more complicated. Only recently (PRX 10, 031004, 2020; with my team’s participation) room temperature, current-driven amplification of incoming THz radiation has been demonstrated in an innovative double grating gate structures based on graphene, one of the most promising materials for plasmonics. These break-through results indicate that existing models of plasmonic systems should be reconsidered and that using new 2D materials or their heterojunctions with innovative geometries, may lead “Towards on-chip plasmonics amplifiers of THz radiation”, which is TERAPLASM’s main objective. The experimental methodology will involve fabrication and THz spectroscopy studies of graphene and alternative-to-graphene unique HgTe and GaN-based systems with a high mobility 2D electron gas. This will allow finding the physical mechanisms responsible for the observed THz plasmonic amplification and select the optimum systems for THz devices. In parallel, theoretical research will develop physical models of THz plasmonic amplification studied in the experimental part of the project. By conducting extensive technological, spectroscopic, and theoretical research TERAPLASM will aim to answer the old basic physics and electronics questions on the feasibility of on-chip plasmonics amplifiers of THz radiation, with important potential applications in wireless telecommunication, biosensing, security, and others.

Lasers are ubiquitous in science and technology, with applications ranging from optical communications and quantum technologies to metrology and sensing and to life sciences and medical diagnostics. However, most commercially used lasers are still based on legacy optical schemes. These devices are either bulky and expensive limiting product development, or lack the ability to quickly sweep or precisely control the laser wavelength, which is key to many applications. At the same time, the advent of advanced photonic integration platforms such as silicon photonics has opened new perspectives, realized only for exascale data centers in telecommunication wavelengths around 1310 and 1550 nm. AgiLight aims at establishing a new class of integrated lasers that can address the entire wavelength range from the blue (400 nm) to the infrared (2.7 µm). These devices rely on a hybrid integration platform that combines ultra-low-loss silicon nitride photonic circuits with advanced tuning actuators and with III-V gain elements, exploiting highly scalable assembly concepts based on 3D printing. The devices will offer high output powers (> 100 mW), down to Hz-level laser linewidths, and unprecedented frequency agility with nanosecond response times and wideband tunability. Comprising leading European research groups and high-tech start-ups as well as a major industrial player, AgiLight will translate ground-breaking research to rapid technology uptake and tailor laser systems for atomic and molecular physics and optics, distance ranging and sensing using the expertise of end-users. The project covers the theoretical and nanofabrication foundations of the envisaged light sources as well as their implementation and functional demonstration in highly relevant research applications throughout the visible and near-infrared spectrum. AgiLight will lay the foundation for an all-European value chain of a novel class of light sources, covering the III-V and low-loss PICs.

The present proposal aims to realise an integrated pilot line focused on the developments of the wide–bandgap (WBG) semiconductors technologies for power and radio frequency (RF) electronics. The project will be realised by strengthening the existing facilities located in Finland, Italy, Poland, France, Austria, Germany and Sweden, and involving Universities and Research centres of the seven above-mentioned States operating in the field of advanced semiconductors and related technologies. The WBG semiconductor pilot lines will address all the front–end critical issues related to the realisation of devices with power and RF performance much higher than those realised by the conventional silicon technology, will define a clear roadmap for the development of such advanced technologies, will investigate strategies to improve the structural and electrical properties of WBG (and Ultra–WBG) semiconductors, and will develop new MEMS devices based on WBG and Ultra-WBG devices.