122 citations · 778 across the 40 of their papers we have counts for
40 papers
Anisotropic Cylindrical Waves in a Square Lattice of Acoustic Waveguides
Ioannis Ioannou Sougleridis, Olivier Richoux, Vassos Achilleos +2
We investigate the propagation of cylindrical waves in a square network of acoustic waveguides. We establish, both theoretically and experimentally, the anisotropic dispersion rela…
Insensitive nonreciprocal edge breathers
Bertin Many Manda, Vassos Achilleos
We uncover subtle and previously unexplored phenomena arising from the interplay of nonlinearity and nonreciprocity in topological mechanical metamaterials. We study a nonreciproca…
Solution of Wave Acceleration and Non-Hermitian Jump in Nonreciprocal Lattices
Sayan Jana, Bertin Many Manda, Vassos Achilleos +2
The time evolution of initially localized wavepackets in the discrete Hatano-Nelson lattice displays a rich dynamical structure shaped by the interplay between dispersion and nonre…
Energy transport and chaos in a one-dimensional disordered nonlinear stub lattice
Su Ho Cheong, Arnold Ngapasare, Vassos Achilleos +3
We investigate energy propagation in a one-dimensional stub lattice in the presence of both disorder and nonlinearity. In the periodic case, the stub lattice hosts two dispersive b…
Gradient catastrophe and Peregrine soliton in nonlinear flexible mechanical metamaterials
Antoine Demiquel, Vassos Achilleos, Georgios Theocharis +1
We explore the generation of extreme wave events in mechanical metamaterials using the regularization of the gradient catastrophe theory developed by A. Tovbis and M. Bertola for t…
Direct experimental observation of total absorption and loss compensation using sound waves with complex frequencies
Anis Maddi, Gaelle Poignand, Vassos Achilleos +2
In this study, we experimentally investigate the application of a transient signal with complex frequencies to the absorption and transmission of sound waves. Indeed, the emission…
Harnessing Nonlinearity to Tame Wave Dynamics in Nonreciprocal Active Systems
Sayan Jana, Bertin Many Manda, Vassos Achilleos +2
We present a mechanism to generate unidirectional pulse-shaped propagating waves, tamed to exponential growth and dispersion, in active systems with nonreciprocal and nonlinear cou…
A nonreciprocal and tunable active acoustic scatterer
Anis Maddi, Gaelle Poignand, Vassos Achilleos +2
A passive loudspeaker mounted in a duct acts as a reciprocal scatterer for plane waves impinging on either of its sides. However, the reciprocity can be broken by means of an asymm…
Envelope vector solitons in nonlinear flexible mechanical metamaterials
Antoine Demiquel, Vassos Achilleos, Georgios Theocharis +1
In this paper, we employ a combination of analytical and numerical techniques to investigate the dynamics of lattice envelope vector soliton solutions propagating within a one-dime…
Robustness of perfect transmission resonances to asymmetric perturbation
Ioannis Kiorpelidis, Panayotis Kalozoumis, Georgios Theocharis +3
We investigate the impact of asymmetric perturbations on the perfect transmission resonances (PTRs) of one-dimensional finite periodic systems. With no perturbations, the scatterin…
Insensitive edge solitons in a non-Hermitian topological lattice
Bertin Many Manda, Vassos Achilleos
In this work, we demonstrate that the synergetic interplay of topology, nonreciprocity and nonlinearity is capable of unprecedented effects. We focus on a nonreciprocal variant of…
Skin modes in a nonlinear Hatano-Nelson model
Bertin Many Manda, Ricardo Carretero-González, Panayotis G. Kevrekidis +1
Non-Hermitian lattices with non-reciprocal couplings under open boundary conditions are known to possess linear modes exponentially localized on one edge of the chain. This phenome…
Emergent non-Hermitian models
Lumen Eek, Anouar Moustaj, Malte Röntgen +3
The Hatano-Nelson and the non-Hermitian Su-Schrieffer-Heeger model are paradigmatic examples of non-Hermitian systems that host non-trivial boundary phenomena. In this work, we use…
Latent Su-Schrieffer-Heeger models
Malte Röntgen, Xuelong Chen, Wenlong Gao +5
The Su-Schrieffer-Heeger (SSH) chain is the reference model of a one-dimensional topological insulator. Its topological nature can be explained by the quantization of the Zak phase…
Exact analogue of the Hatano-Nelson model in 1D continuous nonreciprocal systems
Anis Maddi, Yves Auregan, Guillaume Penelet +2
We propose a general framework that enables the exact mapping of continuous nonreciprocal 1D periodic systems to the Hatano-Nelson (HN) model. Our approach, based on the two-port t…
Equireflectionality and customized unbalanced coherent perfect absorption in asymmetric waveguide networks
Malte Röntgen, Olivier Richoux, Georgios Theocharis +4
We explore the scattering of waves in designed asymmetric one-dimensional waveguide networks. We show that the reflection between two ports of an asymmetric network can be identica…
Topologically invisible defects in chiral mirror lattices
Antonin Coutant, Li-Yang Zheng, Vassos Achilleos +3
One of the hallmark of topological insulators is having conductivity properties that are unaffected by the possible presence of defects. In this work, we go beyond backscattering i…
Wave-packet spreading in the disordered and nonlinear Su-Schrieffer-Heeger chain
Bertin Many Manda, Vassos Achilleos, Olivier Richoux +2
We numerically investigate the characteristics of the long-time dynamics of a single-site wave-packet excitation in a disordered and nonlinear Su-Schrieffer-Heeger model. In the li…
Modulation instability in nonlinear flexible mechanical metamaterials
Antoine Demiquel, Vassos Achilleos, Georgios Theocharis +1
In this paper, we study modulation instabilities (MI) in a one-dimensional chain configuration of a flexible mechanical metamaterial (flexMM). Using the lumped element approach, fl…
Acoustic solitons in a periodic waveguide: theory and experiments
Ioannis Ioannou Sougleridis, Olivier Richoux, Vassos Achilleos +3
We study the propagation of high-amplitude sound waves, in the form of pulse-like solitary waves, in an air-filled acoustic waveguide of periodically varying cross section. Our num…
Wave-packet spreading in disordered soft architected structures
Arnold Ngapasare, Georgios Theocharis, Olivier Richoux +2
We study the dynamical and chaotic behavior of a disordered one-dimensional elastic mechanical lattice which supports translational and rotational waves. The model used in this wor…
Subwavelength Su-Schrieffer-Heeger topological modes in acoustic waveguides
Antonin Coutant, Vassos Achilleos, Olivier Richoux +2
Topological systems furnish a powerful way of localizing wave energy at edges of a structured material. Usually this relies on Bragg scattering to obtain bandgaps with nontrivial t…
Energy spreading, equipartition and chaos in lattices with non-central forces
Arnold Ngapasare, Geogios Theocharis, Olivier Richoux +2
We numerically study a one dimensional, nonlinear lattice model which in the linear limit is relevant to the study of bending (flexural) waves. In contrast with the classic one dim…
Disorder-induced topological phase transition in a 1D mechanical system
Xiaotian Shi, Ioannis Kiorpelidis, Rajesh Chaunsali +3
We numerically investigate the topological phase transition induced purely by disorder in a spring-mass chain. We employ two types of disorders - chiral and random types - to explo…