Eugenio DelRe @ Sapienza

Spatial Solitons and Confirmation of Replica Symmetry Breaking

EDR's group (Eugenio DelRe) experimentally investigates optical spatial solitons and out-of-equilibrium complexity-driven optical dynamics in photorefractive near-transition ferroelectrics. Experiments in 2017 have allowed the observation of Replica Symmetry Breaking (Nature Communications 2017), a result that was explicitly mentioned in the Scientific Background to the 2021 Nobel Prize in Physics as an important confirmation of Giorgio Parisi's framework ("Importantly, experimental evidence of replica symmetry breaking has been provided ... in nonlinear optical propagation through photorefractive disordered waveguides [90]"- Scientifc Background on the Nobel Prize in Physics 2021, Nobel Committee for Physics, 2021,  https://www.nobelprize.org/uploads/2021/10/sciback_fy_en_21.pdf). Details can also be found in C. Conti and E. DelRe, Nature Photonics (2021)  https://doi.org/10.1038/s41566-021-00933-5 . Recent studies are focused on the experimental analysis of Fermi-Pasta-Ulam Recurrences (PRX 2017), soliton chaos (PRL 2021), and the development of an understanding of optical rogue waves (PRL 2015).  Key to these pioneering achievements has been the ability of EDR's systems to study phenomena in full 2+1D, a technique that, developed over more than 2 decades in EDR's laboratory, has been recently funded through the PRIN 2020 project "Extreme waves emerging in full 2D+1 dimensional environments", of which EDR is the Sapienza Unit Leader and responsible for the project experimental activity.

Scale-Free Optics, a new field that allows Subwavelength Beam Propagation, Topological Wave Transitions, and Superlensing

Starting in 2011 EDR's group has opened a new field in photonics that emerges when photoinduced charge diffusion counters diffraction in nanodisordered ferroelectrics, a field termed Scale-Free Optics (Nature Photonics 2011). It allows the wholly counterintuitive propagation of subwavelength beams (Nature Photonics 2015), topological wave transitions and even macroscopic superlensing (Nature Communications 2021).

Ferroelectric Supercrystals, Mesoscopic Topological Phases, and Giant Broadband Refraction

EDR's group experimentally investigates the physics associated to the breaking of spatial inversion symmetry in ferroelectric crystals.  In 2016 the group discovered that during the ferroelectric transition, a coherent ordered 3D domain mosaic forms, a ferroelectric Supercrystal (Nature Communications 2016).  The phase involves high-dimensional topological defects that appear to allow a giant broadband refraction (n>25) across the entire visible and near infrared spectrum (Nature Photonics 2018).  The result has substantial applicative consequences in terms of miniaturized circuitry and nonlinear optics, both that are actively investigated in the group (funded through the H2020 Attract Consortium).  EDR group is presently dedicated to understanding how giant refraction can emerge without absorption.  At present, the investigation is carried out, also in collaboration with other groups, using optical propagation, XRD, Raman Spectroscopy, Optical Spectroscopy, nonlinear optics, phase-contrast microscopy, and piezo-force microscopy.  The present understanding revolves around the formation of hyper-dimensional topological defects, 3D structures characterized by 6 independent vortices.  The phase has numerous still open features, such a full 3D percolative regime with observable fractal behavior (PRL 2021). 

Complex solids - Experimental      

Relaxor ferroelectrics; non-ergodic ferroelectric phases; ageing; dipolar glasses; giant electro-optic response.

Soliton-based electro-optic waveguides in paraelectric crystals; Funnel-wave guide circuits and arrays; volume integrated reprogrammable phase, intensity, and polarization modulators; reprogrammable electro-optic routers, splitters, and filters.

Imaging and super-resolution       

Bessel-beam imaging through turbid media; miniaturized Bessel-beam electro-optic generators; structured illumination; super-resolved THz imaging.

Quantum optics    

Foundations; entanglement; quantum algorithms; single-photons in random fibers.

Statistical Mechanics

Weak-ergodicity breaking, nano-scale fluctuations; Markovian processes.

Laser links, secure space communications and drone-based links

Use of polarization encoding for free-space-optics for space applications; use of drone transponders for ground-to-ground laser links, an applicative activity funded by Lazio Innova (Aerospazio 2018, Gruppi di Ricerca 2020) in collaboration with private sector industrial partners.