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As a typical application of photon momentum transfer, optical levitation systems are known for their ideal isolation from mechanical dissipation and thermal noise. These characters offer extraordinary potential for acceleration precision sensing and have attracted extensive attention in both fundamental and applied physics. Although considerable improvements of optical levitation accelerometers has been reported, the dynamic testing of the sensing performance remains a crucial challenge before the utilization in practical application scenarios. In this work, we present a dual-beam optical levitation accelerometer and demonstrate the test with dynamic inputs for the first time. An acceleration sensing sensitivity of $0.1\mu g$ and a measurement range of $ 1g$ are achieved. These advancements solidify the potential of optical levitation accelerometer for deployment in practical domains, including navigation, intelligent driving, and industrial automation, building a bridge between the laboratory systems and real-world applications., Comment: 17 pages, 6 figures

We consider the reliable implementation of an adaptive high-order unfitted finite element method on Cartesian meshes for solving elliptic interface problems with geometrically curved singularities. We extend our previous work on the reliable cell merging algorithm for smooth interfaces to automatically generate the induced mesh for piecewise smooth interfaces. An $hp$ a posteriori error estimate is derived for a new unfitted finite element method whose finite element functions are conforming in each subdomain. Numerical examples illustrate the competitive performance of the method., Comment: 32 pages

Low-frequency (LF) wireless communications play a crucial role in ensuring anti-interference, long-range, and efficient communication across various environments. However, in conventional LF communication systems, their antenna size is required to be inversely proportional to the wavelength, so that their mobility and flexibility are greatly limited. Here we introduce a novel prototype of LF receiving antennas based on optically levitated nanoparticles, which overcomes the size-frequency limitation to reduce the antenna size to the hundred-nanometer scale. These charged particles are extremely sensitive to external electric field as mechanical resonators, and their resonant frequencies are adjustable. The effectiveness of these antennas was experimentally demonstrated by using the frequency shift keying (2FSK) modulation scheme. The experimental results indicate a correlation between error rate and factors such as transmission rate, signal strength, and vacuum degree with a signal strength of approximately 0.1V/m and a bit error rate below 0.1%. This advancement in leveraging levitated particle mechanical resonators (LPMRs) as LF antennas marks a significant stride in long-distance communication technology.

We introduce Jais and Jais-chat, new state-of-the-art Arabic-centric foundation and instruction-tuned open generative large language models (LLMs). The models are based on the GPT-3 decoder-only architecture and are pretrained on a mixture of Arabic and English texts, including source code in various programming languages. With 13 billion parameters, they demonstrate better knowledge and reasoning capabilities in Arabic than any existing open Arabic and multilingual models by a sizable margin, based on extensive evaluation. Moreover, the models are competitive in English compared to English-centric open models of similar size, despite being trained on much less English data. We provide a detailed description of the training, the tuning, the safety alignment, and the evaluation of the models. We release two open versions of the model -- the foundation Jais model, and an instruction-tuned Jais-chat variant -- with the aim of promoting research on Arabic LLMs. Available at https://huggingface.co/inception-mbzuai/jais-13b-chat, Comment: Arabic-centric, foundation model, large-language model, LLM, generative model, instruction-tuned, Jais, Jais-chat

Searching for three-dimensional spatiotemporal solitons (also known as light/optical bullets) has recently attracted keen theoretical and experimental interests in nonlinear physics. Currently, optical lattices of diverse kinds have been introduced to the stabilization of light bullets, while the investigation for the light bullets of gap type -- nonlinear localized modes within the finite gap of the underlying linear Bloch spectrum -- is lacking. Herein, we address the formation and stabilization properties of such light gap bullets in periodic media with defocusing nonlinearity, theoretically and in numerical ways. The periodic media are based on two-dimensional periodic standing waves created in a coherent three-level atomic system which is driven to the regime of electromagnetically induced transparency, which in principle can also be replaced by photonic crystals in optics or optical lattices in ground-state ultracold atoms system. The temporal dispersion term is tuned to normal (positive) group velocity dispersion so that to launch the light gap bullets under self-repulsive nonlinearity; two types of such light gap bullets constructed as 3D gap solitons and vortices with topological charge m=1 within the first finite gap are reported and found to be robustly stable in the existence domains. On account of the light bullets were previously limited to the semi-infinite gap of periodic media and continuous nonlinear physical systems, the light gap bullets reported here thus supplement the missing type of three-dimensional spatiotemporal localized modes in periodic media which exhibit finite band gaps.

We propose efficient and parallel algorithms for the implementation of the high-order continuous time Galerkin method for dissipative and wave propagation problems. By using Legendre polynomials as shape functions, we obtain a special structure of the stiffness matrix which allows us to extend the diagonal Pad\'e approximation to solve ordinary differential equations with source terms. The unconditional stability, $hp$ error estimates, and $hp$ superconvergence at the nodes of the continuous time Galerkin method are proved. Numerical examples confirm our theoretical results., Comment: 34 pages, 1 figure

We propose a high order unfitted finite element method for solving timeharmonic Maxwell interface problems. The unfitted finite element method is based on a mixed formulation in the discontinuous Galerkin framework on a Cartesian mesh with possible hanging nodes. The $H^2$ regularity of the solution to Maxwell interface problems with $C^2$ interfaces in each subdomain is proved. Practical interface-resolving mesh conditions are introduced under which the hp inverse estimates on three-dimensional curved domains are proved. Stability and hp a priori error estimate of the unfitted finite element method are proved. Numerical results are included to illustrate the performance of the method.

We consider the reliable implementation of high-order unfitted finite element methods on Cartesian meshes with hanging nodes for elliptic interface problems. We construct a reliable algorithm to merge small interface elements with their surrounding elements to automatically generate the finite element mesh whose elements are large with respect to both domains. We propose new basis functions for the interface elements to control the growth of the condition number of the stiffness matrix in terms of the finite element approximation order, the number of elements of the mesh, and the interface deviation which quantifies the mesh resolution of the geometry of the interface. Numerical examples are presented to illustrate the competitive performance of the method., Comment: 34 pages, 20 figures

Nanomechanical resonator based on levitated particle exhibits unique advantages in the development of ultrasensitive electric field detector. We demonstrate a three-dimensional, high-sensitivity electric field measurement technology using the optically levitated nanoparticle with a known net charge. By changing the relative position between nanoparticle and parallel electrodes, the three-dimensional electric field distribution is scanned. The measured noise equivalent electric intensity with charge amount of 100 reaches the order of {\rm{1\mu V/cm/H}}{{\rm{z}}^{{\rm{1/2}}}} at 1.4 \times {10^{ - 7}}mbar. Linearity analysis near resonance frequency shows a measured linear range over 91dB limited only by the maximum output voltage of the driving equipment. This work may provide avenue for developing a high-sensitive electric field sensor based on optically levitated nano-resonator., Comment: 15 pages, 10 figures. arXiv admin note: text overlap with arXiv:2008.05871 by other authors

Electromagnetically induced optical (or photonic) lattices via atomic coherence in atomic ensembles have recently received great theoretical and experimental interest. We here conceive a way to generate electromagnetically induced moir\'{e} optical lattices -- a twisted periodic pattern when two identical periodic patterns (lattices) are overlapped in a twisted angle ($\theta$) -- in a three-level coherent atomic gas working under electromagnetically induced transparency. We show that, changing the twisted angle and relative strength between the two constitutive sublattices, the moir\'{e} Bloch bands that are extremely flattened can always appear, resembling the typical flat-band and moir\'{e} physics found in other contexts. Dynamics of light propagation in the induced periodic structures demonstrating the unique linear localization and delocalization properties are also revealed. Our scheme can be implemented in a Rubidium atomic medium, where the predicted moir\'{e} optical lattices and flattened bands are naturally observable.

In this paper, we propose a novel high order unfitted finite element method on Cartesian meshes for solving the acoustic wave equation with discontinuous coefficients having complex interface geometry. The unfitted finite element method does not require any penalty to achieve optimal convergence. We also introduce a new explicit time discretization method for the ODE system resulting from the spatial discretization of the wave equation. The strong stability and optimal $hp$-version error estimates both in time and space are established. Numerical examples confirm our theoretical results., Comment: 47 pages, 13 figures

In this work, we investigate the regularized solutions and their finite element solutions to the inverse source problems governed by partial differential equations, and establish the stochastic convergence and optimal finite element convergence rates of these solutions, under pointwise measurement data with random noise. Unlike most existing regularization theories, the regularization error estimates are derived without any source conditions, while the error estimates of finite element solutions show their explicit dependence on the noise level, regularization parameter, mesh size, and time step size, which can guide practical choices among these key parameters in real applications. The error estimates also suggest an iterative algorithm for determining an optimal regularization parameter. Numerical experiments are presented to demonstrate the effectiveness of the analytical results.

We theoretically study the spatial focusing of surface polaritons (SPs) in a negative index metamaterial (NIMM)-atomic gas interface waveguide system, based on cross phase modulation (XPM) in a tripod type double electromagnetically induced transparency (EIT) scheme. In the linear region, we realize the low loss stable propagation of SPs, and the group velocities of the probe and signal fields are well matched via double EIT. In the nonlinear region, we show that giant enhancement of the XPM can be obtained. Using a narrow optical soliton in free space, we realize spatial focusing of the SPs solitons, including bright, multi bright, and dark solitons. The full width at the half-maximum (FWHM) of the SPs soliton can be compressed to about ten nanometers, thus, even nanofucsing can be obtained. The results obtained here have certain theoretical significance for micro-nano optics, and also have application potentials in nano-scale sensing, spectral enhancement and precision measurement., Comment: 20 pages, 5figures