arXiv subjects

Rodrigo A. Vicencio

Publications and source records attributed to Rodrigo A. Vicencio.

At least 19 recordsLinked to original sources

arXiv2026

Phase-controlled transport of Floquet-driven compact chiral photonic states

The Aharonov-Bohm (AB) effect remains a cornerstone of fundamental and applied physics. In this work, we utilize the AB caging effect originated from an effective magnetic field induced by multiorbital interactions, creating an all flat band (FB) lattice system. Normally, FB states are known for being compact in space and having a zero tail; therefore, their mobility in a linear environment is generally understood as impossible. We propose a Floquet driving protocol in an all-FB photonic system to fully control the dynamics of localized photonic states. The modulation of the Hamiltonian along the propagation coordinate allows the translation of compact states in the direction of constructive interference, resulting in an effective stroboscopic quantum walk-like effect. We find that the traveling states exist in chiral pairs. We experimentally implement the Floquet driven protocol using femtosecond laser written photonic waveguides and demonstrate directional control of the propagation, determined by the relative phase of the input condition.

physics.optics↗

arXiv2026

Observation of complete delocalization in disordered photonic lattices

We present the exceptional phenomenon of complete absence of Anderson localization, and perfect transmission of particles, in a completely disordered diamond-dot chain. We analytically show a proof for the condition to observe this exceptional phenomenon, based on a transparent window emerging from a geometrical condition. We support our theoretical prediction by numerical simulations and direct experimental observation of the transmission probabilities of the light in a femtosecond laser-written diamond-dot photonic lattices. We additionally show that for a $π$ effective magnetic flux, extreme localization of the light in the same system may occur, independently on the specific geometry. Our results open up an excellent platform for controlling the transmission of energy from ballistic to zero transmission, in a completely disordered lattice system..

cond-mat.dis-nn↗

arXiv2025

Long-range evanescent coupling through photonic molecules

Photonic molecules support the excitation of higher-order states, which are otherwise hard to access at individual waveguides. In this work, we demonstrate the resonant excitation of photonic molecular states which evanescently couple to single-mode waveguides. We implement the experiments on femtosecond laser written photonic structures and demonstrate an efficient resonant excitation of higher-orbital states, optimized at specific wavelengths and propagation distances. We suggest the use of long photonic molecules as long-distance photonic links, and demonstrate strong coupling for very distant waveguides separated by 127 μm. We apply this concept to a one-dimensional lattice and demonstrate the excitation of topological edge states emerging due to the third-order next-neighbour interactions. Our findings demonstrate effective long-range evanescent coupling which could be a concrete solution for fiber-based photonic chips, topological physics emerging from long-range interactions, or fundamental studies of initially uncoupled systems.

physics.optics↗

arXiv2025

Observation of multi-orbital Fano resonances in photonic lattices

Fano resonances are a fundamental physical phenomenon that occurs when an open channel couples with a closed one, resulting in a resonant cancellation of transmission. In this article, we introduce a quantum simulator designed to observe multi-orbital Fano resonances using a photonic waveguide analog. The system consists of a homogeneous lattice, which includes a plane wave generator, and an atom-like impurity that supports first-order (S) and second-order (P) modes. We derive a two-impurity Fano-Anderson model to describe this system and fit the experimental results accordingly, demonstrating a remarkable agreement between our experimental measurements and theoretical predictions. A comprehensive experimental characterization reveals clear double resonances for the S and P states, which depend on the properties of the atom and the excitation wavelength. Our results illustrate how the transport of a propagating beam on a lattice can be effectively controlled by simply adjusting the properties of a single external atom-like impurity, which works as an efficient energy valve.

physics.optics↗

arXiv2025

Quantum storage with flat bands

The realization of robust quantum storage devices relies on the ability to generate long-lived, spatially localized quantum states. In this work, we introduce a method for the targeted creation of compact excitations in flat-band lattices. By injecting in-plane radiation waves from the system's edge and applying a localized on-site potential at the desired storage position, we induce hybridization between compact localized states (CLSs) of the flat-band and resonant dispersive plane waves. This hybridization enables the formation of spatially compact, stable excitations suitable for quantum memory applications. We experimentally validate this mechanism using photonic waveguide arrays, focusing on two representative geometries: the diamond chain and the one-dimensional Lieb ladder. Our approach is broadly applicable to any platform supporting flat-band physics.

physics.optics↗

arXiv2025

Observation of non-Markovian Radiative Phenomena in Structured Photonic Lattices

The spectral structure of a photonic reservoir shapes radiation phenomena for embedded quantum emitters. We implement an all-optical analog to study such an effect, particularly to observe the non- Markovian radiation dynamics of an emitter coupled to two-dimensional structured reservoirs. Its dynamics is simulated by light propagating through a photonic lattice, acting as a reservoir for an adjacent waveguide that mimics a coupled quantum emitter. We study radiation dynamics in square and Lieb lattices under different coupling regimes and observe how the flat band properties of the Lieb lattice significantly enhances light-matter coupling and non-Markovianity. Our platform opens a path for the experimental exploration of single-photon quantum optical phenomena in structured reservoirs to enhance light-matter interactions.

quant-ph↗

arXiv2025

Nonsymmetric evanescent coupling in photonics

Asymmetrical interactions are ubiquitous in nature, and in physics their study becomes fundamental. Despite the prevalence of evanescent coupling in physics, little attention has been paid to wave function profiles, with symmetrical reciprocal interactions often assumed for practical reasons. This work challenges that assumption by analytically demonstrating the origin of nonsymmetrical coupling in a photonic platform, focusing on the behavior of evanescent tails from adjacent waveguides. We experimentally validate an asymmetrical dynamics by studying detuned photonic directional couplers, fabricated via femtosecond laser writing, and corroborate our findings through continuous numerical simulations.

physics.optics↗

arXiv2025

Anomalous localization of light in one-dimensional Lévy photonic lattices

Localization of coherent propagating waves has been extensively studied over the years, primarily in homogeneous random media. However, significantly less attention has been given to wave localization in inhomogeneous systems, where the standard picture of Anderson localization does not apply, as we demonstrate here. We fabricate photonic lattices with inhomogeneous disorder, modeled by heavy-tailed $α$-stable distributions, and measure the output light intensity profiles. We demonstrate that the spatial localization of light is described by a stretched exponential function, with a stretching parameter $α$, and an asymmetric localized profile with respect to the excitation site. We support our experimental and theoretical findings with extensive tight-binding simulations.

cond-mat.dis-nn↗

arXiv2024

Observation of the magic angle and flat band physics in dipolar photonic lattices

Evanescently coupled waveguide arrays provide a tabletop platform to realize a variety of Hamiltonians, where physical waveguides correspond to the individual sites of a tight-binding lattice. Nontrivial spatial structure of the waveguide modes enriches this picture and uncovers further possibilities. Here, we demonstrate that the effective coupling between $p$-like modes of adjacent photonic waveguides changes its sign depending on their relative orientation vanishing for a proper alignment at a so-called magic angle. Using femtosecond laser-written waveguides, we demonstrate this experimentally for $p$-mode dimers and graphene-like photonic lattices exhibiting quasi-flat bands at this angle. We observe diffraction-free propagation of corner and bulk states providing a robust experimental evidence of a two-dimensional Aharonov-Bohm-like caging in an optically switchable system.

physics.optics↗

arXiv2024

Observation of topologically protected compact edge states in flux-dressed graphene photonic lattices

Systems with engineered flatband spectra are a postulate of high-capacity transmission links and a candidate for high-temperature superconductivity. However, their operation relies on the edge or surface modes susceptible to fluctuations and fabrication errors. While the mode robustness can be enhanced by a combination of Aharonov-Bohm caging and topological insulation, the design of the corresponding flatbands requires approaches beyond the standard $k$-vector-based methods. Here, we propose a synthetic-flux probe as a solution to this problem and a route to the realization of ultra-stable modes. We prove the concept in a laser-fabricated graphene-like ribbon photonic lattice with the band-flattening flux induced by "P" waveguide coupling. The topological non-triviality is witnessed by an integer Zak phase derived from the mean chiral displacement. Mode stability is evidenced by excellent mode localization and the robustness to fabrication tolerances and variations of the input phase. Our results can serve as a basis for the development of multi-flat-band materials for low-energy electronics.

cond-mat.mes-hall↗

arXiv2023

Harnessing collective radiative phenomena on a photonic kagome lattice

Photonic lattices enable experimental exploration of transport and localization phenomena, two of the mayor goals in physics and technology. In particular, the optical excitation of some lattice sites which evanescently couple to a lattice array emulates radiation processes into structured reservoirs, a fundamental subject in quantum optics. Moreover, the simultaneous excitation of two sites simulates collective phenomena, leading to phase-controlled enhanced or suppressed radiation, namely super and subradiance. This work presents an experimental study of collective radiative processes on a photonic kagome lattice. A single or simultaneous -- in or out-of-phase -- excitation of the outlying sites controls the radiation dynamics. Specifically, we demonstrate a controlable transition between a fully localized profile at the two outlying sites and a completely dispersed state into the quasi-continuum. Our result presents photonic lattices as a platform to emulate and experimentally explore quantum optical phenomena in two-dimensional structured reservoirs, while harnessing such phenomena for controlling transport dynamics and implementing all-optical switching devices.

physics.optics↗

arXiv2023

Photonic molecule approach to multi-orbital topology

The concepts of topology provide a powerful tool to tailor the propagation and localization of light. While electromagnetic waves have only two polarization states, engineered degeneracies of photonic modes provide novel opportunities resembling orbital or spin degrees of freedom in condensed matter. Here, we tailor such degeneracies for the array of femtosecond laser written waveguides in the optical range exploiting the idea of photonic molecules -- clusters of strongly coupled waveguides. In our experiments, we observe the emergence of topological modes caused by the inter-orbital coupling and track multiple topological transitions in the system with the change of the lattice spacings and excitation wavelength. This strategy opens an avenue in designing novel types of photonic topological phases and states.

physics.optics↗

arXiv2023

Spectral edge-to-edge topological state transfer in diamond photonic lattices

Transfer of information between topological edge states is a robust way of spatially manipulating quantum states while preserving their coherence in lattice environments. This method is particularly efficient when the edge modes are kept within the topological gap of the lattice during the transfer. In this work we show experimentally the transfer of photonic modes between topological edge states located at opposite ends of a dimerized one-dimensional photonic lattice. We use a diamond lattice of coupled waveguides and show that the transfer is insensitive both to the presence of a high density of states in the form of a flat band at an energy close to that of the edge states, and to the presence of disorder in the hoppings. We explore dynamics in the waveguide lattice using wavelength-scan method, where different input wavelength translates into different effective waveguide length. These results open the way to the implementation of more efficient protocols based on the active driving of the hoppings.

physics.optics↗

arXiv2022

Controlled transport based on multiorbital Aharonov-Bohm photonic caging

The induction of synthetic magnetic fields on lattice structures allows to effectively control their localization and transport properties. In this work, we generate effective $π$ magnetic fluxes on a multi-orbital diamond lattice, where first ($S$) and second ($P$) order modes effectively interact. We implement a $z$-scan method on femtosecond laser written photonic lattices and experimentally observe Aharonov-Bohm caging for $S$ and $P$ modes, as a consequence of a band transformation and the emergence of a spectrum composed of three degenerated flat bands. As an application, we demonstrate a perfect control of the dynamics, where we translate an input excitation across the lattice in a completely linear and controlled way. Our model, based on a flat band spectrum, allows us to choose the direction of transport depending on the excitation site or input phase.

cond-mat.other↗

arXiv2021

Experimental observation of inter-orbital coupling

Inter-orbital coupling refers to the possibility of exciting orbital states by otherwise orthogonal non-interacting modes, a forbidden process in photonic lattices due to an intrinsic propagation constant detuning. In this work, using a femtosecond laser writing technique, we experimentally demonstrate that fundamental and excited orbital states can couple each other when located at different spatial positions. We perform a full characterization of an asymmetric double-well like potential and implement a scan method to effectively map the dynamics along the propagation coordinate. Our fundamental observation constitutes also a direct solution for a spatial mode converter device, which could be located in any position inside a photonic glass chip. By taking advantage of the phase structure of higher-order photonic modes and the effective negative coupling generated, we propose a trimer configuration as a phase beam splitter ($π$-BS), which could be of great relevance for multiplexing and interference-based photonic concatenated operations.

cond-mat.other↗

arXiv2019

Perfect localization on flat band binary one-dimensional photonic lattices

The existence of flat bands is generally thought to be physically possible only for dimensions larger than one. However, by exciting a system with different orthogonal states this condition can be reformulated. In this work, we demonstrate that a one-dimensional binary lattice supports always a trivial flat band, which is formed by isolated single-site vertical dipolar states. These flat band modes correspond to the highest localized modes for any discrete system, without the need of any aditional mechanism like, e.g., disorder or nonlinearity. By fulfilling a specific relation between lattice parameters, an extra flat band can be excited as well, with modes composed by fundamental and dipolar states that occupy only three lattice sites. Additionally, by inspecting the lattice edges, we are able to construct analytical Shockley surface modes, which can be compact or present staggered or unstaggered tails. We believe that our proposed model could be a good candidate for observing transport and localization phenomena on a simple one-dimensional linear photonic lattice.

physics.optics↗

arXiv2017

Observation of Ground and Excited Flat Band States in Graphene Photonic Ribbons

Understanding the wave transport and localisation is a major goal in the study of lattices of different nature. In general, inhibiting the energy transport on a perfectly periodic and disorder-free system is challenging, however, some specific lattice geometries allow localisation due to the presence of dispersionless (flat) bands in the energy spectrum. Here, we report on the experimental realisation of a quasi-one-dimensional photonic graphene ribbon supporting four flat-bands. We study the dynamics of fundamental and dipolar modes, which are analogous to the s and p orbitals, respectively. In the experiment, both modes (orbitals) are effectively decoupled from each other, implying two sets of six bands, where two of them are completely flat. Using an image generator setup, we excite the s and p flat band modes and demonstrate their non-diffracting propagation for the first time. Our results open an exciting route towards photonic emulation of higher orbital dynamics.

physics.optics↗

arXiv2017

All-optical logic gates in Stub photonic lattices

We experimentally study a Stub photonic lattice and excite their localized linear states originated from an isolated Flat Band at the center of the linear spectrum. By exciting these modes in different regions of the lattice, we observe that they do not diffract across the system and remain well trapped after propagating along the crystal. By using their wave nature, we are able to combine -- in phase and out of phase -- two neighbor states into a coherent superposition. These observations allow us to propose a novel setup for performing three different all-optical logical operations such as OR, AND, and XOR, positioning Flat Band systems as key setups to perform concrete applications at any level of power.

physics.optics↗