Article
Physics, Applied
B. Deng, J. R. Raney, K. Bertoldi, V. Tournat
Summary: Flexible mechanical metamaterials are compliant structures engineered to achieve unique properties through large deformations of their components. While their static properties have been extensively studied, research on their dynamic properties, especially in the nonlinear regime induced by their high deformability, is still in its early stages. Recent studies have shown that these systems offer new opportunities for controlling large-amplitude elastic waves.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Acoustics
Harold Berjamin
Summary: Introduces simple strain-rate viscoelasticity models for isotropic soft solids. The constitutive equations consider finite strain, incompressibility, material frame-indifference, nonlinear elasticity, and viscous dissipation. Nonlinear viscous wave equation for shear strain is obtained exactly and corresponding one-way Burgers-type equations are derived through standard approximations. Analysis of travelling wave solutions reveals distinct solutions for these partial differential equations, with deviations amplified for non-arbitrarily small wave amplitudes. In the elastic limit, the one-way approximate wave equation can be connected to simple wave theory and shock wave theory, facilitating direct error measurements.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Optics
Y. Cao, T. F. Xu
Summary: We studied gap solitons and nonlinear Bloch waves in Kerr nonlinear systems under competition between quadratic and quartic dispersions. The results show that nonlinear Bloch waves can still be regarded as infinite fundamental gap solitons chains. We also revealed the properties of the gap solitons in the relevant band gaps by numerical analysis.
Article
Nanoscience & Nanotechnology
Gauthier Roubaud, Sebastien Bidault, Sylvain Gigan, Samuel Gresillon
Summary: By using statistical imaging schemes, direct insight on both localized and delocalized plasmonic modes featured by disordered gold metasurfaces is provided. The ability of wavefront shaping to control optical properties depends strongly on the nanoscale morphology of the sample. Close to the percolation threshold, the entire surface is sensitive to wavefront shaping, resulting in the observation of the largest densities of delocalized modes and strongest optical hotspots.
Article
Materials Science, Multidisciplinary
Ba Phi Nguyen, Duy Khuong Phung, Kihong Kim
Summary: We numerically investigate the time evolution of wave packets in one-dimensional semi-infinite lattices with mosaic modulated random on-site potentials. We find that the long-time behavior of the time-dependent reflectance obeys a power law, indicating the onset of Anderson localization or classical diffusion. The phenomena of delocalization occur at certain discrete values of the central energy and depend on the modulation period. We provide an analytical formula for the quasiresonance energies and explain the delocalization phenomenon based on the interplay between randomness and band structure. The states at the quasiresonance energies are found to be critical states through finite-size scaling analysis.
Article
Multidisciplinary Sciences
Zhetao Jia, Matteo Secli, Alexander Avdoshkin, Walid Redjem, Elizabeth Dresselhaus, Joel Moore, Boubacar Kante
Summary: Complex networks are crucial in understanding phenomena like collective behavior of spins, neural networks, power grids, and disease spread. Recent studies have used topological phenomena in these networks to maintain system response in the presence of disorder. This article proposes and demonstrates topological structurally disordered systems with enhanced nonlinear phenomena in the topological channels. The construction of the graph and its dynamics significantly increase the rate of topologically protected photon pair generation. Disordered nonlinear topological graphs can enable advanced quantum interconnects, efficient nonlinear sources, and light-based information processing for artificial intelligence.
Article
Acoustics
Giuseppe Saccomandi, Maurizio S. Vianello
Summary: The study presents a one-dimensional rheological model for the propagation of linearly polarized shear waves, which can also derive the equations governing the propagation of circularly polarized shear waves. The research shows that, under appropriate asymptotic assumptions, the results are indifferent to the choice of the objective time derivative used.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Sergi Lendinez, Mojtaba T. Kaffash, Olle G. Heinonen, Sebastian Gliga, Ezio Iacocca, M. Benjamin Jungfleisch
Summary: We have discovered the existence of nonlinear magnon-magnon scattering processes and their coherence in ensembles of magnetic nanostructures known as artificial spin ice. Utilizing a combined microwave and microfocused Brillouin light scattering measurement approach, we have found that these systems exhibit effective scattering processes akin to those observed in continuous magnetic thin films. Our results suggest that frequency doubling is enabled by exciting a subset of nanomagnets that act as nanosized antennas, which is similar to scattering in continuous films. Furthermore, directional scattering could be possible in these structures.
NATURE COMMUNICATIONS
(2023)
Article
Mechanics
Fanli Liu, Moran Wang
Summary: This study investigates the impact of wettability distribution, pore size distribution and pore geometry on trapping behavior during capillary displacement. The trapping patterns are determined by four dimensionless control parameters and the dependence of patterns on these parameters is obtained, aiding in understanding the influence of wettability and structure on trapping behavior in disordered media.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Wenhai Lei, Wenbo Gong, Moran Wang
Summary: The preferential flow-induced non-monotonic wettability effect has been found to be consistent in different disordered media. Under preferential flow conditions, the balance of microscopic imbibition ability and macroscopic interfacial stability dominates the invading process.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Sen Wang, Tiao-Jian Xu, Kan-Min Shen, Bin Wang, Guo-Hai Dong, Tong-Yan Wang
Summary: This study explores the impact of the nonlinear strengths of sloshing on the damping performance of side-mounted perforated baffles and examines the influence of these baffles on the resonance characteristics of sloshing flow. Two models, a microscopic model and a volume-averaged macroscopic model, are used to simulate the sloshing flow in a 2D water tank with perforated baffles. Experimental tests are conducted to validate the numerical model. The critical Reynolds number for the nonlinear strength is found to be 56,000, beyond which an increase in nonlinear strength has little effect on damping performance and instead leads to increased sloshing response due to strong interaction between baffles and fluid flow. The Reynolds number corresponding to the critical nonlinear strength is independent of the properties of the perforated baffles. Additionally, increasing the blockage of perforated baffles significantly weakens the resonance effect of sloshing flow, accompanied by a decrease in the maximum force amplitude on the bulkhead.
Article
Materials Science, Multidisciplinary
S. Basak, M. Alzate Banguero, L. Burzawa, F. Simmons, P. Salev, L. Aigouy, M. M. Qazilbash, I. K. Schuller, D. N. Basov, A. Zimmers, E. W. Carlson
Summary: The capabilities of image probe experiments are rapidly expanding, providing new information about quantum materials on unprecedented length-and timescales. Image recognition techniques from machine learning are an excellent tool for interpreting information encoded in the spatial relationships in such images. The development of a deep learning framework allows us to discover the underlying Hamiltonian driving the pattern formation.
Article
Physics, Multidisciplinary
Pedro A. M. Mediano, Fernando E. Rosas, Adam B. Barrett, Daniel Bor
Summary: The study aims to quantify the effects of spectral and phasic influences on the differences in nonlinear features between two systems through a decomposition method, adding nuance to a wide range of time series analyses.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Xudong Liang, Alfred J. Crosby
Summary: In this study, we investigate the dynamic recoil that couples with a general nonlinear power-law interaction within a metamaterial framework. Our findings reveal that nonlinear force interactions and elastic structures in metamaterials can control the dynamic performance. We also discover a sonic vacuum response in the recoiling metamaterials, where a near-zero speed of sound is induced by strongly nonlinear interactions and zero initial prestress. Moreover, we find that the nonlinear wave speed has a non-monotonic dependence upon the strength of the power-law interaction. Our analytical model shows good agreements with experimental results, providing insights for new materials designs in high-rate applications.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Physics, Multidisciplinary
Pankaj Sarma, Pralay Kumar Karmakar
Summary: A nonlinear nonideal generalized magnetohydrodynamic model is developed to explore the evolutionary dynamics of nonlinear wave-structural patterns in inhomogeneous protoplanetary disks. The excitation of nonlinear coherent structures in the form of solitary lump waves is demonstrated through a numerical illustrative platform. The study investigates the characteristics of these solitary lump waves geometrically through phase space trajectories.
CHINESE JOURNAL OF PHYSICS
(2021)
News Item
Optics
Claudio Conti, Eugenio Delre
Article
Physics, Multidisciplinary
Massimo Materassi, Giulia Marcucci, Claudio Conti
Summary: This article introduces a dissipative model defined by a metriplectic structure, consisting of a pair of tensors and a free energy, used to characterize the dynamics generator. The model is applied to describe the process of two-photon absorption, with the Hamiltonian component describing the free electromagnetic radiation and the metric component modeling purely dissipative dynamics.
Article
Multidisciplinary Sciences
Mauro Missori, Laura Pilozzi, Claudio Conti
Summary: This study proposes a terahertz photonic structure composed of dielectric rods layers made by low-cost, rapid, and versatile 3D printing. The spectral and dynamic response of the structures are studied using terahertz time-domain spectroscopy. The results show that the structures have specific spectral forbidden bands dependent on their optical and geometrical parameters and evidence of disorder in the 3D printed structure. The diffusion coefficient of terahertz radiation in the structures is estimated by studying the dynamics diffusion of the pulses.
SCIENTIFIC REPORTS
(2022)
Article
Optics
Angela Capocefalo, Silvia Gentilini, Lorenzo Barolo, Paola Baiocco, Claudio Conti, Neda Ghofraniha
Summary: Highly accurate biosensors are crucial in fields such as healthcare and environmental monitoring. We propose the use of polymeric whispering gallery microlasers as biosensors for detecting small amounts of proteins, down to 400 pg. These photonic microsensors can be easily patterned on microscope slides and operate in air and solution. We also describe the sensing ability of passive spherical resonators in the presence of dielectric nanoparticles that mimic proteins using extensive numerical simulations.
PHOTONICS RESEARCH
(2023)
Article
Physics, Multidisciplinary
Claudio Conti
Summary: Nonlocal quantum fluids play important roles in dark-matter models, quantum simulations, and technologies. This study explores the dynamics of 3D+1 solitons in the second-quantized nonlocal nonlinear Schrodinger-Newton equation, and theoretically investigates the quantum diffusion of soliton parameters. The numerical simulations validate the theoretical analysis and reveal the onset of non-Gaussian statistics, which have potential implications for quantum computing.
NEW JOURNAL OF PHYSICS
(2023)
Article
Optics
Laura Pilozzi, Mauro Missori, Claudio Conti
Summary: In this study, the transition from Fano resonances to Bound states in the continuum (BIC) in a one-dimensional photonic crystal slab made of rectangular dielectric rods was investigated at terahertz frequencies. Symmetry-protected, high-Q BIC were found at normal incidence through simulations based on an analytical exact solution of the Maxwell equations. For non-normal incidence, BIC coupled with freely propagating waves and appeared as Fano resonances in the scattering field. The simulations were validated by 3D-printing the photonic crystal slab and comparing THz time-domain spectroscopy measurements.
Article
Multidisciplinary Sciences
Davide Pierangeli, Claudio Conti
Summary: The authors present a method for single shot polarimetry of vector beams without using polarization optics. They use light scattering to map the polarization content of the beam into a spatial intensity distribution and utilize supervised learning for single-shot measurements of multiple polarizations. This method enables accurate characterization of structured light encoding multiple polarizations and has the potential to impact optical devices for sensing, imaging, and computing.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Davide Pierangeli, Giordano Perini, Valentina Palmieri, Ivana Grecco, Ginevra Friggeri, Marco De Spirito, Massimiliano Papi, Eugenio DelRe, Claudio Conti
Summary: The authors discovered that tumor-cell spheroids exhibit optical rogue waves under randomly modulated laser beam illumination. The intensity of transmitted light follows a Weibull statistical distribution, with extreme events corresponding to localized optical modes propagating within the cell network. These nonlinear optical filaments form high-transmission channels and can be used to achieve controlled temperature increase. This study sheds light on optical propagation in biological aggregates and demonstrates the potential of using rogue waves in biomedical applications.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Yu-xuan Ren, Joshua Lamstein, Chensong Zhang, Claudio Conti, Demetrios N. Christodoulides, Zhigang Chen
Summary: Rogue-wave-like events have been discovered in human red blood cell suspensions, which are attributed to the phase modulation caused by the biconcave shape and mutable orientation of the suspended red blood cells. Numerical simulations and experiments show that these events may also exist in other cellular environments, and understanding their underlying physics is of great significance.
PHOTONICS RESEARCH
(2023)
Article
Optics
Riccardo Falcone, Claudio Conti
Summary: In this study, we investigate the detection of Unruh radiation using ionized hydrogenlike atoms accelerated by an external electric field. We find that the first-quantized description for hydrogenlike atoms is not always applicable due to the frame-dependent definition of particles. However, we show that this frame-dependent effect can be suppressed by constraining the atomic ionization and the electric field. Additionally, we identify the physical regimes where atomic excitation probability exists due to the Unruh electromagnetic background, and determine the observational limits for the Unruh effect using first-quantized atomic detectors.
Article
Astronomy & Astrophysics
Riccardo Falcone, Claudio Conti
Summary: This article presents the representation of the Minkowski vacuum as an element of the Rindler-Fock space for a free Dirac field in flat spacetime. The statistical operator obtained by tracing away the left wedge is computed, and the resulting thermal state for fermionic particles is described.
Article
Astronomy & Astrophysics
Riccardo Falcone, Claudio Conti
Summary: From first principles, we derive the nonrelativistic limit of scalar and Dirac fields in curved spacetime. Our aim is to find general relativistic corrections to the quantum theory of particles affected by Newtonian gravity, which is currently experimentally accessible. By rigorously determining these corrections through the nonrelativistic limit of fully relativistic quantum theories in curved spacetime, we show how a noninertial observer can distinguish between a scalar field and a Dirac field in curved static spacetimes. For sufficiently large acceleration, the gravity-spin coupling dominates over the corrections for scalar fields, making Dirac particles the best candidates for observing non-Newtonian gravity in quantum particle phenomenology.
Article
Optics
Riccardo Falcone, Claudio Conti
Summary: We demonstrate that Minkowski single-particle states located beyond the horizon can alter the Unruh thermal distribution in an accelerated frame, thus allowing accelerated observers to detect particles emitted beyond the horizon contrary to classical predictions. Our approach is based on deriving the explicit Wigner characteristic function for the complete description of the quantum field in the noninertial frame, and it can be extended to general states.
Article
Optics
Gianni Jacucci, Louis Delloye, Davide Pierangeli, Mushegh Rafayelyan, Claudio Conti, Sylvain Gigan
Summary: The study demonstrates the possibility of controlling the couplings of a fully connected Ising spin system through optics, enabling the modification of Ising Hamiltonian and solving complex spin-glass Hamiltonians.
Article
Nanoscience & Nanotechnology
Zhen-Ting Huang, Kuo-Bin Hong, Ray-Kuang Lee, Laura Pilozzi, Claudio Conti, Jhih-Sheng Wu, Tien-Chang Lu
Summary: In this study, a straightforward and effective design approach for photonic topological insulators supporting high quality factors edge states is proposed using pattern-tunable strain-engineering. Chiral strain-engineering creates opposite synthetic gauge fields in two domains resulting in Landau levels with the same energy spacing but different topological numbers. The strain strongly affects the degree of localization of edge states, while the two-domain design stabilizes the strain-induced topological edge state, providing large scalability for various photonics applications.
