Integrated perovskite-polariton circuits for spin logic 

National Science Center of Poland No. 2024/55/B/ST3/02954

Particles in the quantum world possess a fundamental quantized property known as “spin” which, like charge of an electron, could revolutionize information processing technologies. Spin-dependent interactions between quantum particles and their transport in condensed matter are essential for solid-state spintronic devices, where the electron spin offers faster, denser, and more reliable data storage and processing. However, controlling electron spin is challenging due to short lifetimes and low mobility under normal conditions. By combining photonic and electronic properties through strong light-matter coupling, the emerging field of spinoptronics addresses these challenges. Semiconductor microcavities host exciton-polaritons, hybrid particles with spinor properties that exhibit ultrafast response, long lifetimes, superfluid transport, and strong optical nonlinearities. These features make polaritons ideal for integrated photonic circuits capable of efficient spin-based signal processing.

Current polariton spin switches and logic components are bulky, operate at low temperatures, and lack scalability. Advancing polariton-based spinoptronics requires room-temperature operation in compact, interconnected circuits controlled by both electrical and optical inputs. Achieving this would revolutionize spin-based optical computing for digital, analog, and neuromorphic applications while enabling quantum technologies like entangled photon sources.

This project, led by the University of Warsaw, aims to create room-temperature polariton circuits using lead-halide perovskites and liquid crystal technologies. High-quality perovskite microwires with strong spin interactions will be combined with electric-field-tunable liquid crystals for precise control. Theoretical work will guide the design of spin-switches, logic gates, and transistors, with experimental validation providing proof-of-concept for integrated polariton circuits. Success will pave the way for on-chip optical computing with high speed, energy efficiency, and photonic parallelism.

Interacting networks of liquid light

National Science Center of Poland No. 2022/45/P/ST3/00467

Microscale optical resonators are devices which efficiently confine photons long enough to interact strongly with embedded matter such as semiconductor quantum wells. The electronic excitations within absorb and reemit the confined photons at such high rates that a new mixture of light and matter emerges known as exciton-polaritons. These emergent bosonic light-matter quasiparticles can form macroscopic quantum fluids, sometimes referred as “liquid light” or “polariton Bose-Einstein condensates”, at elevated temperatures. Polariton condensates have numerous exotic properties not found in many other condensed matter systems such as superfluidity, quantized vorticity, ultralow threshold lasing, spontaneous synchronization like in Huygens’ clocks experiment, and self-organized behaviours through their nontrivial dynamics.

Motivated by recent advancements in material design and patterned light sources to generate coherent large-scale polariton networks, we aim to design novel and necessary theoretical frameworks to underpin the quality of polariton networks as platforms for reprogrammable analogue many-body simulation and unconventional neural-inspired optical computation. Theoretical outcomes are communicated to partner laboratories who will help demonstrate proof of concept, unleashing the potential disruptive performance of this new highly nonlinear technological platform in the strong light-matter coupling regime. Application of reprogrammable ultralow threshold coherent polariton networks, integrated on-chip, touches upon topological lasers, subpicosecond optical spin switches, simulating extreme many-body systems to generate new scholarly knowledge, optimization of complex energy functions, and task-specific optical neuromorphic computation which could help solve pressing problems requiring on-the-fly optimization with impact on material synthesis, drug design, financial prediction, logistics, and much more.

 Supported by the National Science Center of Poland under the projects 2024/55/B/ST3/02954 and 2022/45/P/ST3/00467 co-funded by the European Union Framework Programme for Research and Innovation Horizon 2020 under the Marie Skłodowska-Curie grant agreement No. 945339.