Nonlinear Physics

Author(s): Ivan Sekulic, Ji Tong Wang, Jian Wei You, and Nicolae C. PanoiuThe problem of solving nonlinear scattering of optical waves from arbitrary distributions of particles becomes practically intractable when the number of particles is larger than just a few. Here, the authors introduce an approach based on multiple-scattering matrix theory that solves this problem for clusters of thousands of particles of arbitrary shape made of materials characterized by general frequency-dispersion relations, so that it describes the optical response of metallic, semiconductor, and polaritonic particles. To illustrate the versatility of the method, the enhancement of second-harmonic generation in a cluster of particles that supports bound-states in the continuum at both the fundamental frequency and second harmonic is demonstrated. [Phys. Rev. B 112, 035426] Published Mon

Synthetic antiferromagnets are carefully engineered magnetic materials made up of alternating ferromagnetic layers with oppositely aligned magnetic moments, separated by a non-magnetic spacer. These materials can display interesting magnetization patterns, characterized by swift changes in the behavior of magnetic moments in response to external forces, such as radio frequency (RF) currents.

The generation of electricity from heat, also known as thermoelectric energy conversion, has proved to be advantageous for various real-world applications. For instance, it proved useful for the generation of energy during space expeditions and military missions in difficult environments, as well as for the recovery of waste heat produced from industrial plants, power stations or even vehicles.

Many systems obey simple, linear rules: If you pull twice as hard on a spring, it stretches twice as far. However, when we introduce very large forces or complicated interactions, that linear rule breaks down into a "nonlinear" regime.

In a review just published in Nature Materials, researchers take aim at the oldest principle in electronics: Ohm's law.

Breaking inversion symmetry in materials allows deviations from Ohm's law, enabling nonlinear effects that could drive future nano- and quantum-electronic devices.

Author(s): Adam Anglart, Paweł Obrępalski, Agnès Maurel, Philippe Petitjeans, and Vincent PagneuxThe authors experimentally investigate here the Su-Schrieffer-Heeger model in a periodic water wave channel, observing robust topological edge modes consistent with theoretical predictions and 2D simulations. Remarkably, these sloshing modes localized at the boundaries persist under nonlinear excitation, where bifurcations and secondary resonances emerge. This work connects topological physics and fluid mechanics, providing an accessible platform for exploring wave localization, symmetry protection, and nonlinear dynamics in classical wave systems. [Phys. Rev. B 111, 224311] Published Mon Jun 30, 2025

Author(s): Weijian JiaoTo overcome the limitations of regular perturbation methods that fail to correctly capture some unusual nonlinear dispersion behaviors, the author proposes here an equivalent eigenvalue approach that converts the nonlinear wave equation to an equivalent linear eigenvalue problem. This directly gives the nonlinear dispersion relation and modal vectors. The theoretical approach is employed to 1D and 2D phononic crystals with alternating softening and hardening nonlinearities, revealing nonlinearity-induced band-gap opening and closing phenomena and achieving tunable frequency splitting and focusing effects. [Phys. Rev. B 111, 214308] Published Mon Jun 30, 2025

Author(s): A. Sud, K. Yamamoto, S. Iihama, K. Ishibashi, S. Fukami, H. Kurebayashi, and S. MizukamiApplying a strong enough radio frequency current to a synthetic antiferromagnet leads to nonlinear magnon-magnon coupling and Rabi-like splitting of the signal while preserving the symmetries of the system. [Phys. Rev. Lett. 134, 246704] Published Fri Jun 20, 2025

Author(s): Shulin Wang, Bing Wang, Chenyu Liu, Chengzhi Qin, Lange Zhao, Weiwei Liu, Stefano Longhi, and Peixiang LuA concept based on an exotic effect in periodic structures may be useful for developing future photonic devices. [Phys. Rev. Lett. 134, 243805] Published Fri Jun 20, 2025

Author(s): Clément Stahl, Denis Werth, and Vivian PoulinSharp features in the primordial power spectrum are a natural prediction of many UV-complete models of inflation. The authors use dedicated N-body simulations to demonstrate that features consistent with CMB constraints persist throughout the nonlinear regime of structure formation and thus may play a role in explaining tensions between the CMB and observations of the late-time matter distribution. While further numerical work is necessary to resolve the degeneracy with other effects, this study is a pioneering foundation for future research. [Phys. Rev. D 111, 123514] Published Tue Jun 10, 2025

Author(s): Alexander Wilzewski et al.A hypothetical fifth force could be detected by its effect on the optical transition frequencies of an element’s different isotopes. [Phys. Rev. Lett. 134, 233002] Published Tue Jun 10, 2025

Author(s): Octavio Albarrán, Renata Garcés, Giacomo Po, Christoph F. Schmidt, and Jeff D. EldredgeBacterial cell walls maintain integrity under high turgor pressure through a covalently linked peptidoglycan network. This study models the E . c o l i cell wall using a hyperelastic framework, suggesting that strain hardening underlies pressure-dependent stiffness and providing insights for further quantitative studies. #BiophysicsSpotlight #Interdisciplinary [Phys. Rev. E 111, 064405] Published Mon Jun 02, 2025

Author(s): Daniel P. Keane, Elnaz Nikoumanesh, Krutarth M. Kamani, Simon A. Rogers, and Ryan Poling-SkutvikFor a wide range of complex fluids, the transition from solid-like at rest to liquid-like when pushed can be predicted from properties of the at-rest state. [Phys. Rev. Lett. 134, 208202] Published Fri May 23, 2025

Researchers have long recognized that quantum communication systems would transmit quantum information more faithfully and be impervious to certain forms of error if nonlinear optical processes were used. However, past efforts at incorporating such processes could not operate with the extremely low light levels required for quantum communication.

Researchers have long recognized that quantum communication systems would transmit quantum information more faithfully and be impervious to certain forms of error if nonlinear optical processes were used. However, past efforts at incorporating such processes could not operate with the extremely low light levels required for quantum communication.

Author(s): Jörg Frauendiener, Chris Stevens, and Sebenele ThwalaFor the first time, a gravitational wave impinging onto a static black hole has been numerically simulated by including nonlinearity and with a computational domain from past to future null-infinity. [Phys. Rev. Lett. 134, 161401] Published Wed Apr 23, 2025

Researchers developed a scalable fabrication process using soft nanoimprint lithography to create lithium niobate metalenses, enabling efficient nonlinear optics through enhanced second-harmonic generation

Author(s): S. Mirzaei-Ghormish and Ryan M. Camacho, the light-induced self-organization of particles, is essential in levitated optomechanics, nanomaterials, and quantum optics. Conventional models are limited to linear optical interactions, though, and lack tunable mechanisms for trap stabilization or reconfiguration that do not involve moving the optical fields themselves. This work develops a theory of nonlinear optical binding that produces surprising equilibrium configurations, tunable trap periodicities, and enhanced stability at subwavelength separations, with no beam shaping or external fields. These results may provide a concrete pathway for power-controlled particle assembly and programmable optical matter. [Phys. Rev. Applied 23, 044044] Published Mon Apr 21, 2025

Neural networks are one typical structure on which artificial intelligence can be based. The term neural describes their learning ability, which to some extent mimics the functioning of neurons in our brains. To be able to work, several key ingredients are required: one of them is an activation function which introduces nonlinearity into the structure. A photonic activation function has important advantages for the implementation of optical neural networks based on light propagation. Researchers have now experimentally shown an all-optically controlled activation function based on traveling sound waves. It is suitable for a wide range of optical neural network approaches and allows operation in the so-called synthetic frequency dimension.

Author(s): Yu-jiang Dong, Xinghao Wang, Jianmin Zheng, Weiliang Qiao, Rui-Rui Du, Loren N. Pfeiffer, Kenneth W. West, and Kirk W. BaldwinNonlinear transport studies are performed to investigate the low-temperature behavior of a CF-2 Wigner solid surrounded by fractional quantum Hall liquid. The electric-field-temperature duality phenomenon of a Wigner solid was observed, which is interpreted within the Berezinskii-Kosterlitz-Thouless phase transition model. [Phys. Rev. Research 7, L022011] Published Wed Apr 09, 2025

Author(s): Xu Zheng and Y. D. ChongA rigorous analysis of noise–nonlinearity interplay at exceptional points reveals new challenges for non-Hermitian sensing. [Phys. Rev. Lett. 134, 133801] Published Thu Apr 03, 2025

A research team from the Xinjiang Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences has made strides in the theoretical design of nonlinear optical (NLO) materials by leveraging machine learning techniques. The team introduced a new strategy to explore uncharted chemical spaces, enabling the quantitative prediction of second harmonic generation (SHG) coefficients for complex NLO systems spanning infrared to deep ultraviolet wavelengths.

The El Niño-Southern Oscillation (ENSO), the most prominent interannual climate variability signal, has been widely studied for its teleconnections with Antarctic sea ice variability. However, its influence on the predictability of Antarctic sea ice remains poorly understood, hindering the development of accurate sea ice prediction models.

Author(s): Angelo Caravano, Gabriele Franciolini, and Sébastien Renaux-PetelScenarios like u l t r a s l o w − r o l l Inflation significantly change the final stages of slow-roll inflation to create large curvature perturbations that produce gravitational waves (GW) and primordial black holes (PBH). These phases are outside the usual

Author(s): Francesca Mignacco, Chi-Ning Chou, and SueYeon ChungDespite progress in artificial intelligence and neuroscience, the theoretical understanding of how neural networks learn complex functions remains sparse. One promising avenue involves analyzing the geometric properties of network representations, i.e., the activity of neural populations, and their impact on task performance using statistical physics methods. Existing approaches have been restricted to linear probes. The authors overcome this limitation by proposing a theoretical framework to address non-linearly-separable representations leveraging contextual information, a ubiquitous paradigm in brain computation. The findings allow for future investigations into high-dimensional representation efficiency and analyses of biological and artificial datasets, promising relevant implications for

Researchers from Oakland University have made a significant breakthrough in the field of optical materials, unveiling the exceptional capabilities of Ba₃(ZnB₅O₁₀)PO₄ (BZBP). Although this transparent crystal closely resembles ordinary window glass, it exhibits extraordinary properties that set it apart from others.

A team of researchers has identified a unique phenomenon, a "skin effect," in the nonlinear optical responses of antiferromagnetic materials. The research, published in Physical Review Letters, provides new insights into the properties of these materials and their potential applications in advanced technologies.

Nonlinear dynamical systems are systems that can undergo sudden shifts not due to changes in their state or stability, but in response to the rate at which external conditions or parameters change. These sudden shifts, known as noise-induced and rate-induced tipping, can make predicting how the systems will shift over time more challenging.

Author(s): Abigail Postlewaite, Arpit Raj, Swati Chaudhary, and Gregory A. FieteMultilayered graphene systems provide a highly tunable platform to study quantum geometric effects. Here, the authors show that the quantum geometry of electronic bands in rhombohedral trilayer graphene leads to a large shift-current response which can be tuned by applying a displacement field perpendicular to the layers. The authors compare the response with Bernal stacked bilayer graphene and find additional features arising due to the confluence of quantum geometry and the multiband nature of rhombohedral trilayer graphene. [Phys. Rev. B 110, 245122] Published Tue Dec 10, 2024

Author(s): Valerio Lucarini and Mickaël D. ChekrounResponse theory for nonequilibrium systems provides a basis for optimal fingerprinting in climate system, a framework crucial for linking climate change to both anthropogenic and natural drivers. [Phys. Rev. Lett. 133, 244201] Published Mon Dec 09, 2024

Author(s): K. Dini, H. Sigurðsson, N. W. E. Seet, P. M. Walker, and T. C. H. LiewPolariton neurons allow exciton-polaritons to transport information using a successive local switching in analogy to action potentials in biological neurons. The authors show here an analogue of saltatory conduction for enhancing signal speeds: by connecting bistable nodes with waveguides, polariton signal speeds can be increased tenfold. The modeling of this system requires a new theoretical tool: nonlinear finite-difference time-domain simulation, which accounts for the propagation of light in the full three-dimensional nanostructure together with nonlinear exciton-exciton scattering using Maxwell-Bloch equations. [Phys. Rev. B 110, 214303] Published Wed Dec 04, 2024

Author(s): Yao-Jui Chan, Syed Mohammed Faizanuddin, Raju Kalaivanan, Sankar Raman, Hsin Lin, Uddipta Kar, Akhilesh Kr. Singh, Wei-Li Lee, Ranganayakulu K. Vankayala, Min-Nan Ou, and Yu-Chieh WenNonlinear photocurrents in topological semimetals encode quantum geometric characters of Bloch wavefunctions and band topology, and offer a new opportunity for advanced photovoltaics. Here, the authors characterize the nonlinear photoconductivities of chiral multifold semimetal CoSi through a refined terahertz emission spectroscopy analysis. The results reveal a large linear shift conductivity and confirm a giant nonquantized circular injection conductivity in the mid-infrared range. Bulk transverse injection currents and relatively weak photon drag effect are also identified. [Phys. Rev. B 110, L201118] Published Tue Nov 26, 2024

A team of researchers has successfully demonstrated nonlinear Compton scattering (NCS) between an ultra-relativistic electron beam and an ultrahigh intensity laser pulse using the 4-Petawatt laser. The innovative approach was the usage of only a laser for electron-photon collisions, in which a multi-PW laser is applied both for particle acceleration and for collision (also called an all-optical setup). This achievement represents a significant milestone in strong field physics, in particular strong field quantum electrodynamics (QED), offering new insights into high-energy electron-photon interactions without the need for a traditional mile-long particle accelerator.

A team of researchers has successfully demonstrated nonlinear Compton scattering (NCS) between an ultra-relativistic electron beam and an ultrahigh intensity laser pulse using the 4-Petawatt laser at the Center for Relativistic Laser Science (CoReLS) within the Institute for Basic Science at Gwangju Institute of Science and Technology (GIST), Korea.

Author(s): Debottam Mandal, Sanjay Sarkar, Kamal Das, and Amit AgarwalThe authors develop here a comprehensive framework for third-order electronic transport, focusing on the impact of quantum geometry in materials where conventional responses are absent. By deriving new forms of reciprocal longitudinal and Hall currents in time-reversal symmetry-broken systems, they reveal how quantum geometric features – specifically, the quantum geometric connection and tensor – shape these nonlinear currents. This theoretical advancement provides a blueprint for identifying materials with intrinsic third-order responses, with potential applications in advanced quantum technologies. [Phys. Rev. B 110, 195131] Published Wed Nov 13, 2024

Author(s): Alberto Nardin, Daniele De Bernardis, Rifat Onur Umucalılar, Leonardo Mazza, Matteo Rizzi, and Iacopo CarusottoNonlinear chiral Luttinger liquid theory is able to describe the dynamics of a fractional quantum Hall fluid even on the small lattices that are available to experiments. [Phys. Rev. Lett. 133, 183401] Published Tue Oct 29, 2024

Author(s): Hanxu Zhang, Tao Li, and Xu WangHydrogenlike thorium-229 ions interacting with intense lasers could unlock a highly nonlinear and nonperturbative regime of light-nucleus interaction. [Phys. Rev. Lett. 133, 152503] Published Fri Oct 11, 2024

In recent years, many physicists and materials scientists have been studying a newly uncovered class of magnetic materials known as altermagnets. These materials exhibit a unique type of magnetism that differs from both conventional ferromagnetism and antiferromagnetism, marked by electrons whose spin varies depending on their momentum.

A recent study has unveiled a transformative nonlinear optical metasurface technology. This new technology, characterized by structures smaller than the wavelength of light, paves the way for significant advancements in next-generation communication technologies, including quantum light sources and medical diagnostic devices.

Author(s): Diego García Ovalle, Armando Pezo, and Aurélien ManchonThe optical Kerr effect, widely used for probing magnetic domains, can be used to detect nonequilibrium orbital accumulation, even in the absence of spin-orbit coupling. In certain low-symmetry crystals, this orbital accumulation is associated with a nonlinear Hall effect that can be exploited for terahertz (THz) detection. As a result, the “orbital” Kerr effect is directly related to the THz responsivity of the material. Using first-principles calculations, the authors demonstrate here that this effect in low-symmetry crystals and multilayers can be remarkably large. [Phys. Rev. B 110, 094439] Published Thu Sep 26, 2024

A research team has discovered significant nonlinear Hall and wireless rectification effects at room temperature in elemental semiconductor tellurium (Te). Their research is published in Nature Communications.

Author(s): Sopheak Sorn and Adarsh S. PatriDiscovering long-range hidden orders is a long-standing challenge in the field of unconventional magnetism. Such type of order is elusive to conventional magnetic probes. Here, focusing on the archetypal ferro-octupolar ordering in metallic heavy-fermion compounds, the authors demonstrate through a combination of semiclassical transport and general symmetry analysis that nonlinear Hall transport is the dominant experimental signature. [Phys. Rev. B 110, 125127] Published Wed Sep 11, 2024

Author(s): Emily Z. Zhang, Ciarán Hickey, and Yong Baek KimTwo-dimensional coherent spectroscopy ( 2 D C S ) has emerged as a powerful tool for probing nonlinear excitation dynamics in quantum magnets, overcoming the limitations of traditional inelastic neutron scattering as a linear probe. The authors use here classical molecular dynamics simulations to compare the 2 D C S responses of various models with large Kitaev interactions, revealing distinct features between quantum spin liquids, classical spin liquids, and

Author(s): Yuan Fang, Jennifer Cano, and Sayed Ali Akbar GhorashiInvestigation of the nonlinear response in altermagnets uncovers the role of quantum geometry order by order. [Phys. Rev. Lett. 133, 106701] Published Thu Sep 05, 2024

Author(s): Marric StephensResearchers have isolated a high-order term in the behavior of a Josephson junction, which could lead to longer-lived superconducting qubits. [Physics 17, s107] Published Thu Sep 05, 2024

Author(s): Jonathan Colen, Alexis Poncet, Denis Bartolo, and Vincenzo VitelliA clever use of machine learning guides researchers to a missing term that’s needed to accurately describe the dynamics of a complex fluid system. [Phys. Rev. Lett. 133, 107301] Published Tue Sep 03, 2024

Author(s): Rui Chen, Z. Z. Du, Hai-Peng Sun, Hai-Zhou Lu, and X. C. XieThe nonlinear Hall effect provides a new experimental tool to probe the condensed matter phases. This work presents the first real-space lattice theory of the nonlinear Hall effect, so that strong disorder can be handled to explain an unexpected fluctuation in the experiments and discover a “localization” of the nonlinear Hall effect. The calculation can be generalized to more crystal lattices. [Phys. Rev. B 110, L081301] Published Tue Aug 20, 2024

Author(s): Alexander Frenett, Zack Lasner, Lan Cheng, and John M. DoyleThe authors explore candidates for a next-generation search for the electron electric dipole moment (eEDM) by experimentally measuring the vibrational loss channels in three Sr-containing nonlinear molecules. They conclude that SrNH 2  is the optimal choice for a future laser-cooled molecule-based eEDM experiment. [Phys. Rev. A 110, 022811] Published Wed Aug 14, 2024

In recent research, a scientist from Princeton University has performed the first nonlinear study of the merger of a black hole mimicker, aiming to understand the nature of gravitational wave signals emitted by these objects, which could potentially help to identify black holes more accurately.

A research team led by Dr. Li Yunlong at the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences delved into the origins of nonlinear current response in polycrystalline metal halide perovskite X-ray detectors. Their study was published in ACS Applied Materials & Interfaces on July 14.

Using two optically-trapped glass nanoparticles, researchers observed a novel collective Non-Hermitian and non-linear dynamic driven by non-reciprocal interactions. This contribution expands traditional optical levitation with tweezer arrays by incorporating non-conservative interactions.

UCLA researchers have conducted an in-depth analysis of nonlinear information encoding strategies for diffractive optical processors, offering new insights into their performance and utility. Their study, published in Light: Science & Applications, compared simpler-to-implement nonlinear encoding strategies that involve phase encoding with the performance of data repetition-based nonlinear information encoding methods, shedding light on their advantages and limitations in the optical processing of visual information.

Structured light can significantly enhance information capacity, due to its coupling of spatial dimensions and multiple degrees of freedom. In recent years, the combination of structured light patterns with image processing and machine intelligence has shown vigorous development potential in fields such as communication and detection.

Scientists face many tradeoffs when trying to build and scale up brain-like systems that can perform machine learning.

Author(s): Bethany Clarke, Yongyun Hwang, and Eric E. KeavenyThe follower force model is a fundamental model for active filaments, commonly utilized to model microtubule-motor protein complexes and collections of cilia. In this work we perform a thorough analysis of this model, employing techniques from computational dynamical systems, adapted from high Reynolds number fluid dynamics, to map out the bifurcations in the system and classify emergent states. This approach allows us to bridge the gap between 2D and 3D analyses, in particular establishing the initial buckling as a double Hopf bifurcation. Additionally, we identify the existence of a quasiperiodic solution at the second bifurcation, and categorize the dynamics at higher values of forcing. [Phys. Rev. Fluids 9, 073101] Published Mon Jul 15, 2024

Nonlinear optics is a branch of optics that deals with the complex nonlinear relationships between the optical response of the medium and the incident light when it interacts with the optical medium. Currently, nonlinear optics has been successfully applied to a variety of fields, such as laser modulation, optical signal processing, and medical imaging.

Photochromic compounds, which change their color when exposed to light, have been widely used as photo switches to control different properties of materials. Nonlinear photochromic compounds, characterized by a nonlinear response to the intensity of incident light, have attracted special attention among researchers as the nonlinearity leads to enhanced contrast and improved spatial resolution in photochromic reactions.

Author(s): Arkady Kurnosov, Lucas J. Fernández-Alcázar, Alba Ramos, Boris Shapiro, and Tsampikos KottosA universal, one-parameter scaling theory is developed that describes transport behavior from the ballistic to the diffusive regime in multimode nonlinear photonic circuits. [Phys. Rev. Lett. 132, 193802] Published Wed May 08, 2024

Author(s): Lukas A. Jakob, William M. Deacon, Rakesh Arul, Bart de Nijs, Niclas S. Mueller, and Jeremy J. BaumbergMolecular vibrations play a key role in sensing, catalysis, molecular electronics and beyond, but investigating the coherence and dynamics of individual molecules is extremely challenging. Here, the authors study the vibrational dynamics of ~100 molecules confined in plasmonic nanocavities through simultaneous coherent and incoherent Raman scattering to access both phonon population decay and dephasing. The results show that the dephasing of collective molecular vibrations is accelerated by excitation-power-dependent processes, amplified by the plasmonic near-field enhancement in the cavity. [Phys. Rev. B 109, 195404] Published Thu May 02, 2024

Author(s): Mojtaba Rajabi, Taras Turiv, Bing-Xiang Li, Hend Baza, Dmitry Golovaty, and Oleg D. LavrentovichElectrophoretic transport is greatly enhanced in a nematic environment due to shear thinning. [Phys. Rev. Lett. 132, 158102] Published Thu Apr 11, 2024

Light can compute functions during its propagation and interaction with structured materials, with high speed and low energy consumption. Achieving universal computing using all-optical neural networks requires optical activation layers with nonlinear dependence on input. However, the existing optical nonlinear materials are either slow or have very weak nonlinearity under the natural light intensity levels captured by a camera. Therefore, the design and development of new optical activation functions is essential for realizing optical neural networks that compute with ambient light.

Author(s): Hugh Morison, Jagmeet Singh, Nayem Al Kayed, A. Aadhi, Maryam Moridsadat, Marcus Tamura, Alexander N. Tait, and Bhavin J. ShastriRecurrent neural networks based on silicon photonics can take on a wide range of dynamical features at high bandwidth, but experimental demonstrations are being held back by of the lack of a physical-level simulation platform that accounts for parasitic effects. This study uses photonic Verilog-A models to demonstrate characteristic neural dynamics. Simulation reveals that these dynamics exhibit a topological equivalence to the continuous-time recurrent-neural-network model. [Phys. Rev. Applied 21, 034013] Published Fri Mar 08, 2024

Author(s): Lujunyu Wang, Jiaojiao Zhu, Haiyun Chen, Hui Wang, Jinjin Liu, Yue-Xin Huang, Bingyan Jiang, Jiaji Zhao, Hengjie Shi, Guang Tian, Haoyu Wang, Yugui Yao, Dapeng Yu, Zhiwei Wang, Cong Xiao, Shengyuan A. Yang, and Xiaosong WuResearchers have observed a new class of nonlinear Hall effect that can be understood through a geometric description of the electronic wave function. [Phys. Rev. Lett. 132, 106601] Published Wed Mar 06, 2024

A research team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the University of Salerno in Italy has discovered that thin films of elemental bismuth exhibit the so-called non-linear Hall effect, which could be applied in technologies for the controlled use of terahertz high-frequency signals on electronic chips.

Glass can be synthesized through a novel "crystal-liquid-glass" phase transformation. Crystalline materials can be fine-tuned for desired properties such as improved mass transfer and optical properties through coordination chemistry and grid chemistry design principles.

Author(s): H. Handa, Y. Okamura, R. Yoshimi, A. Tsukazaki, K. S. Takahashi, Y. Tokura, and Y. TakahashiRecent advances in high-field terahertz technologies can unveil the nonlinear response of elementary excitations. This work finds large-amplitude coherent phonon dynamics in the fully anharmonic regime by intense terahertz excitation of the ferroelectric semiconductor In-doped (Sn,Pb)Te. The high-field resonant drive of soft phonons induces the dramatic shift of transient phonon frequency near the ferroelectric transition point. This highly nonlinear terahertz response quantitatively reveals a phonon potential dominated by strong anharmonicity and temporal lattice dynamics with giant atomic displacement. [Phys. Rev. B 109, L081102] Published Fri Feb 02, 2024

Nature is the foremost international weekly scientific journal in the world and is the flagship journal for Nature Portfolio. It publishes the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature publishes landmark papers, award winning news, leading comment and expert opinion on important, topical scientific news and events that enable readers to share the latest discoveries in science and evolve the discussion amongst the global scientific community.

Author(s): A. O. Scheie, Y. Kamiya, Hao Zhang, Sangyun Lee, A. J. Woods, M. O. Ajeesh, M. G. Gonzalez, B. Bernu, J. W. Villanova, J. Xing, Q. Huang, Qingming Zhang, Jie Ma, Eun Sang Choi, D. M. Pajerowski, Haidong Zhou, A. S. Sefat, S. Okamoto, T. Berlijn, L. Messio, R. Movshovich, C. D. Batista, and D. A. TennantQuantum spin liquids were proposed over 50 years ago, but identifying experimental signatures is extremely difficult. Here, the authors study the Yb triangular materials KYbSe 2 and NaYbSe 2 , and show that KYbSe 2 is well described

Scientists are making significant strides in the development of ultrabroadband white laser sources, covering a wide spectrum from ultraviolet to far infrared. These lasers find applications in diverse fields such as large-scale imaging, femto-chemistry, telecommunications, laser spectroscopy, sensing, and ultrafast sciences.

Author(s): Anubhab Haldar, Zhengjie Huang, Xuedan Ma, Pierre Darancet, and Sahar SharifzadehCoherent interactions between electromagnetic waves and extended vibrational degrees of freedom in solids (phonons) enable the stabilization of non-equilibrium states of matter with potentially desirable properties. However, the breakdown of the harmonic approximation in a material experiencing a structural phase transition results in large anharmonic deviations that limit the applicability of standard illumination protocols based on periodic drives. In this study, the authors propose a new illumination protocol that enables amplification of vibrations far into the non-linear regime for broken-symmetry materials. [Phys. Rev. Materials 8, 015202] Published Mon Jan 08, 2024

Author(s): Edith Wietek, Matthias Florian, Jonas Göser, Takashi Taniguchi, Kenji Watanabe, Alexander Högele, Mikhail M. Glazov, Alexander Steinhoff, and Alexey ChernikovInterlayer excitons in van der Waals heterostructures diffuse rapidly, with diffusion coefficients about 1000 times larger than previously seen, in the absence of moiré- and disorder-induced localization. [Phys. Rev. Lett. 132, 016202] Published Thu Jan 04, 2024

Author(s): Dongbin Shin, Angel Rubio, and Peizhe TangCalculations show that light-matter interactions via nonlinear phononics can lead to long-lived non-equilibrium lattice distortion in bulk HgTe, demonstrating a possible microscopic mechanism to control the material topology with light. [Phys. Rev. Lett. 132, 016603] Published Wed Jan 03, 2024

Writing in PRX Quantum, Nathan Goldman and Lucila Peralta Gavensky (Science Faculty, ULB) and their colleagues introduce a general framework for modifying and controlling the nature of nonlinearities in a broad class of physical systems, including optical devices and quantum atomic gases.

Second order surface-specific nonlinear optical spectroscopy, e.g. sum-frequency spectroscopy, has made significant and continuous success in revealing the microscopic structures at surfaces/interfaces since the 1990s.

As a well-known ultraviolet (UV)-vis-near-infrared (IR) nonlinear optical (NLO) material in the borate system, β-BaB2O4 (BBO) has a wide range of applications because of its outstanding NLO performance. Further analysis of the electronic structure of BBO is warranted to clarify the disputes on the second harmonic generation (SHG) mechanism and NLO functional motifs of BBO.

An international team of researchers including a team from the Center for the Advancement of Topological Semimetals (CATS), an Energy Frontier Research Center under the U.S. Department of Energy's Office of Science led by Ames National Laboratory, experimentally demonstrated a new type of nonlinear Hall effect. This Hall effect is driven by the quantum metric, which defines the distances between electronic wavefunctions inside a crystal.

The hardness of a material normally is set by the strength of chemical bonds between electrons of neighboring atoms, not by freely flowing conduction electrons. Now a team of scientists has shown that current-carrying electrons can make the lattice much softer than usual in the material Sr2RuO4.

Author(s): Jude Deschamps, Yun Kai, Jet Lem, Ievgeniia Chaban, Alexey Lomonosov, Abdelmadjid Anane, Steven E. Kooi, Keith A. Nelson, and Thomas PezerilPulsed lasers are routinely used to optically excite and detect ultrasounds in a broad frequency range, from megahertz to terahertz. Though well-established for decades, this technique of laser ultrasonics is constrained by the potential optical damage it may cause to the sample, resulting in the generation of relatively weak pressures, well below kilobars. This study introduces a methodology for the excitation of nondestructive shock waves, at a high repetition rate, limited only by the mechanical strength of the sample. This work establishes a way to repeatedly deliver high-amplitude strain pulses to samples of interest, facilitating the dynamical study of strain-induced phenomena. [Phys.

Author(s): Zhejunyu Jin, Xianglong Yao, Zhenyu Wang, H. Y. Yuan, Zhaozhuo Zeng, Weiwei Wang, Yunshan Cao, and Peng YanNonlinear scattering of magnons and skyrmions in antiferromagnets leads to a spin Hall effect that emerges from real-space topology. [Phys. Rev. Lett. 131, 166704] Published Mon Oct 16, 2023

Exciton polaritons, hybrid quasiparticles caused by the strong exciton-photon coupling, constitute a unique prototype for studying many-body physics and quantum photonic phenomena traditionally in cryogenic conditions.

A team of international researchers led by The University of Hong Kong (HKU) and The University of Science and Technology (HKUST) has made a significant discovery in the field of quantum materials, uncovering the controllable nonlinear Hall effect in twisted bilayer graphene.

An ideal infrared (IR) nonlinear optical (NLO) crystal must have the advantages of a wide transmittance range, impressive laser-induced damage threshold (LIDT), sufficient birefringence index, bulk single-crystal form, and physicochemical stability.

Author(s): Valerio De Luca, Alex Kehagias, and Antonio RiottoRecent pulsar timing array data suggest the presence of stochastic gravitational waves, implying a significant amplitude in curvature perturbations and thus a large abundance of primordial black holes (PBH). The latter is at odds with the observed constraints on the PBH abundance. The authors scrutinize in detail the standard calculation and approximations in determining the PBH abundance and point out several uncertainties, concluding that the PBH abundance is likely much smaller than what is the current consensus. [Phys. Rev. D 108, 063531] Published Thu Sep 28, 2023

A new study by researchers from the Institute of Atmospheric Physics of the Chinese Academy of Sciences challenges traditional climate research frameworks. It demonstrates the pivotal role of nonlinear energy processes in shaping the zonal asymmetry observed in El Niño-Southern Oscillation (ENSO)-induced Pacific-North American (PNA) wave trains.

Higher-order topological insulators are unusual materials that can support topologically protected states. Recently discovered disclination states also belong to the class of higher-order topological states but are bound to the boundary of the disclination defect of the higher-order topological insulator and can be predicted using the bulk-disclination correspondence principle.

Researchers have reported on the first experimental observation of the nonlinear photonic disclination states in waveguide arrays with pentagonal or heptagonal disclination cores inscribed in transparent optical medium using the fs-laser writing technique.

In the intricate world of light, a journey through inhomogeneous media often leads to distortions in space, time, spectrum, and polarization. These distortions, detrimental to applications like optical manipulation, imaging, and communication, have long posed a challenge. Enter the art of wavefront shaping (WS)—a potent tool for correcting these wave maladies in linear optics. But that's not all. Nonlinearity adds a twist, finding purpose in fields from biological sensing to phototherapy. Now, picture combining these forces—nonlinearity and WS—opening doors to unprecedented control.

The instability of Stokes waves (steady propagating waves on the surface of an ideal fluid with infinite depth) represents a fundamental challenge in the realm of nonlinear science. A team of researchers recently identified the origin of breaking oceanic waves in a recent publication in the Proceedings of the National Academy of Sciences.

Researchers establish mathematically the design of a circuit capable of gathering energy from the heat of the earth and storing it in capacitors for later use.

Obtaining useful work from random fluctuations in a system at thermal equilibrium has long been considered impossible. In fact, in the 1960s eminent American physicist Richard Feynman effectively shut down further inquiry after he argued in a series of lectures that Brownian motion, or the thermal motion of atoms, cannot perform useful work.

Author(s): Meizhen Huang, Zefei Wu, Xu Zhang, Xuemeng Feng, Zishu Zhou, Shi Wang, Yong Chen, Chun Cheng, Kai Sun, Zi Yang Meng, and Ning WangAn out-of-plane displacement field substantially affects the nonlinear Hall effect in high-mobility twisted bilayer graphene devices. [Phys. Rev. Lett. 131, 066301] Published Fri Aug 11, 2023

Can one see through a scattering medium like ground glass? Conventionally, such a feat would be deemed impossible. As light travels through an opaque medium, the information contained in the light becomes "jumbled up," almost as if undergoes complex encryption. Recently, Professor Choi Wonshik's team from the IBS Center for Molecular Spectroscopy and Dynamics (IBS CMSD) has discovered a way to utilize this phenomenon in optical computing and machine learning.

Nature is the foremost international weekly scientific journal in the world and is the flagship journal for Nature Portfolio. It publishes the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature publishes landmark papers, award winning news, leading comment and expert opinion on important, topical scientific news and events that enable readers to share the latest discoveries in science and evolve the discussion amongst the global scientific community.

Squeezing light beyond the diffraction limit and controlling the optical processes caused by nano-confined light are central issues of nanophotonics. In particular, localized and enhanced light at the plasmonic nanogaps in scanning probe microscopes provides us with a unique platform for obtaining site-specific optical information at the molecular/atomic scale.

Nature is the foremost international weekly scientific journal in the world and is the flagship journal for Nature Portfolio. It publishes the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature publishes landmark papers, award winning news, leading comment and expert opinion on important, topical scientific news and events that enable readers to share the latest discoveries in science and evolve the discussion amongst the global scientific community.