MARGO project startup

(Image above from Unsplash collection by Spentys )

Our new project within the Graphene Flagship ( Flagera Call JTC 2019) officially started !

MARGO stands for MAxillofacial bone Regeneration by 3D-printed laser-activated Graphene Oxide Scaffolds

MARGO is an exciting data-driven interdisciplinary research on our previous results on the Antibacterial coating and stem cell replication by Graphene Oxide, following our ERC PoC Project VANGUARD!

See also

MARGO project website

Phase space machine learning for multi-particle event optimization in Gaussian boson sampling

We use neural networks to represent the characteristic function of many-body Gaussian states in the quantum phase space. By a pullback mechanism, we model transformations due to unitary operators as linear layers that can be cascaded to simulate complex multi-particle processes. We use the layered neural networks for non-classical light propagation in random interferometers, and compute boson pattern probabilities by automatic differentiation. We also demonstrate that multi-particle events in Gaussian boson sampling can be optimized by a proper design and training of the neural network weights. The results are potentially useful to the creation of new sources and complex circuits for quantum technologies.

https://arxiv.org/abs/2102.12142

Official code

Two-flux tunable Aharonov-Bohm caging in a photonic lattice

We study the Aharonov-Bohm caging effect in a one-dimensional lattice of theta-shaped units defining a chain of interconnected plaquettes, each one threaded by two synthetic flux lines. In the proposed system, light trapping results from the destructive interference of waves propagating along three arms, this implies that the caging effect is tunable and it can be controlled by changing the tunnel couplings J. These features reflect on the diffraction pattern allowing to establish a clear connection between the lattice topology and the resulting AB interference.

arXiv:2102.06682

Topological nanophotonics and artificial neural networks

We propose the use of artificial neural networks to design and characterize photonic topological insulators. As a hallmark, the band structures of these systems show the key feature of the emergence of edge states, with energies lying within the energy gap of the bulk materials and localized at the boundary between regions of distinct topological invariants. We consider different structures such as one-dimensional photonic crystals, PT-symmetric chains and cylindrical systems and show how, through a machine learning application, one can identify the parameters of a complex topological insulator to obtain protected edge states at target frequencies. We show how artificial neural networks can be used to solve the long standing quest of inverse-problems solution and apply it to the cutting edge topic of topological nanophotonics.

Pilozzi et al 2020 Nanotechnology https://doi.org/10.1088/1361-6528/abd508

Experiments on adiabatic evolution in Ising machines in Optica

Combinatorial optimization problems are crucial for widespread applications but remain difficult to solve on a large scale with conventional hardware. Novel optical platforms, known as coherent or photonic Ising machines, are attracting considerable attention as accelerators on optimization tasks formulable as Ising models. Annealing is a well-known technique based on adiabatic evolution for finding optimal solutions in classical and quantum systems made by atoms, electrons, or photons. Although various Ising machines employ annealing in some form, adiabatic computing on optical settings has been only partially investigated. Here, we realize the adiabatic evolution of frustrated Ising models with 100 spins programmed by spatial light modulation. We use holographic and optical control to change the spin couplings adiabatically, and exploit experimental noise to explore the energy landscape. Annealing enhances the convergence to the Ising ground state and allows to find the problem solution with probability close to unity. Our results demonstrate a photonic scheme for combinatorial optimization in analogy with adiabatic quantum algorithms and classical annealing methods but enforced by optical vector-matrix multiplications and scalable photonic technology.

https://www.osapublishing.org/optica/fulltext.cfm?uri=optica-7-11-1535&id=442147

See also https://arxiv.org/abs/2005.08690