An erbium-doped filtered mode-locked fiber laser is demonstrated in this work. Mode-locked operation was achieved using the nonlinear amplifying loop mirror (NALM) technique incorporating a filtering effect. The proposed fiber laser employs a 1.8 m polarization-maintaining fiber (PMF) in the NALM loop, yielding a free spectral range (FSR) of 3.6 nm. The high birefringence of the PMF was utilized for optical filtering to construct the fiber laser. Stable filtered soliton pulses were obtained with a central wavelength of 1566 nm. Upon increasing the pump power to 304 mW and precisely adjusting the polarization controller, filter-induced noise-like solitons centered at 1562.6 nm were generated. This passively mode-locked fiber laser features a simple structure and stable performance, enabling switchable operation between two filtered soliton states, and thus holds significant application potential in fields such as all-optical communication.

An important route toward the preparation of cold molecules is magnetically tunable Feshbach resonances. Here we investigate an inelastic Feshbach resonance between a single pair of {}^{87}\mathrm{R}\mathrm{b} and {}^{39}\mathrm{K} atoms confined in an optical tweezer, with both atoms prepared in the |F=1,m_{\mathrm{F}}=-1⟩ state. By developing an in-situ imaging scheme for {}^{39}\mathrm{K}, we directly measure magnetic-field-dependent collisional loss without separating the atoms after the interaction. For weak confinement, the resonance position measured in our experiment differs from the bulk-gas experiments. In contrast, we observe a significant shift of the resonance toward higher magnetic fields as the tweezer trap depth increases. Coupled-channel calculations accounting for finite temperature effects fail to explain the magnitude of this shift, suggesting that it originates from differential optical responses of the open-channel atom pair and the weakly bound molecular state under strong confinement. Our results indicate that optical tweezer light can significantly modify Feshbach resonance properties, opening a pathway toward optical control of atom–atom interactions and weakly bound molecular states in dual-species tweezer platforms.

The rapid emergence of quantum technology has raised new challenges in distinguishing various quantum circuits of similar functions. In this work, we propose parallel quantum embedding neural network (ParaQuanNet) for the efficient identification of quantum generative circuits via classifications of the corresponding output data. Specifically, we generated W-like states with eight generative quantum circuits realizing the generative quantum denoising diffusion probabilistic models (QDDPM). Our ParaQuanNet can classify these eight classes of generated quantum data with an accuracy of 99.5%, even though all of them are trained to generate the same types of quantum data. With a novel design of parallel quantum embedding unit (PQEU) in our neural networks, our ParaQuanNet enables the quantum kernel circuit parallelly process all the receptive fields of quantum data, which empowers the quantum data processing efficiency. We also integrate the mutual unbiased measurements into our ParaQuanNet and further improve its performance. We apply our ParaQuanNet on the classification of classical data sets and demonstrate a good performance of quantum neural networks on these tasks. Our approach demonstrates good robustness to noisy data and the circuit-level noise with a Python realization in calssical GPU. Our results highlight ParaQuanNet as a scalable and effective framework for quantum circuits identification, contributing to the broader development of quantum machine intelligence.

We report a comprehensive analysis of dynamics of two-dimensional vortex solitons with winding number S=1, maintained by a quadratic time-dependent potential with coefficient \kappa (t)={\kappa }_{\mathrm{d}\mathrm{c}}+{\kappa }_{\mathrm{a}\mathrm{c}}\cos \left(\omega t\right), which may periodically alternate between confinement and expulsion, in a combination with the self-focusing or defocusing cubic nonlinearity. Analytical results are reported for the linear version of the system, which is a nontrivial one too, while the nonlinear system is explored by means of systematic simulations. Fully stable axisymmetric vortex states in the system with the self-focusing nonlinearity are observed with scaled norm N taking values below a critical one, N_{\mathrm{c}\mathrm{r}}. In the interval of , we identify quasi-stable modes, which exhibit periodic splitting into a rotating pair of fragments and their recombination, thus breaking and restoring the axial symmetry. In the adjacent interval, , the system supports rotating robust states composed of two permanently separated fragments. There are no stable modes at N>N_{max}, where the vortices are destroyed by the collapse. In the case of the self-defocusing nonlinearity, the vortices remain stable for arbitrarily large values of the norm. These findings significantly enhance the understanding of the vortex dynamics in systems subject to the time-periodic “management”, which may be realized in atomic Bose−Einstein condensates and bulk optical waveguides.

Electronegativity is a cornerstone of chemical intuition, essential for rationalizing bonding, reactivity, and material properties. However, prevailing scales remain empirically derived, often relying on parameterized models or composite physical quantities. In this work, we introduce a universal electronegativity scale founded on the Atomic Mean Inner Potential (AMIP), also known as the average Coulomb potential, a fundamental, quantum-mechanical property accessible through both first-principles computation and electron-scattering experiments. Our scale, denoted {\chi }_{\mathrm{A}\mathrm{M}\mathrm{I}\mathrm{P},p}, is an analytic function of just three ground-state atomic descriptors and carries explicit physical units. It demonstrates excellent agreement with established scales and successfully classifies bonding types across 358 compounds, including adherence to the metalloid “Si rule”. Beyond replicating known trends, {\chi }_{\mathrm{A}\mathrm{M}\mathrm{I}\mathrm{P},1/2} proves to be a powerful predictive tool, accurately determining Lewis acid strengths for over 14 000 coordination environments (R^2=0.93) and \gamma-ray annihilation spectral widths for 36 elements (R^2=0.97), outperforming previous methods. By linking electronegativity directly to a measurable quantum property, this work provides a unified and predictive descriptor for electronic structure and chemical behavior across the periodic table.

Bismuth oxyiodide (BiOI), a ternary halide oxide with a tunable bandgap and strong UV-visible light absorption, has attracted significant attention for applications in photocatalysis, solar cells, and photodetection. However, its relatively low photocurrent and sluggish photoresponse limit its practical use in high-performance photodetectors. To overcome these challenges, a BiOI/CdS heterojunction photodetector was designed and fabricated, featuring a type-II band alignment to enhance charge separation efficiency. Under ultraviolet illumination (300 nm), the device exhibited an exceptionally high on/off current ratio of 1.82×10⁷, rapid response and recovery times of 72 μs and 244 μs, respectively, a responsivity of 1.54 × 10⁴ A/W, an external quantum efficiency (EQE) of 6.37 × 10⁶ %, and a specific detectivity of 4.08 × 10¹⁴ Jones. These outstanding optoelectronic characteristics highlight the great potential of the BiOI/CdS heterostructure for advanced ultraviolet (UV) imaging and optical communication systems, offering a promising route for the design of next-generation BiOI-based optoelectronic devices.

Two-dimensional (2D) materials exhibit excellent thermoelectric performance attributable to their lower dimensions. Through quantum transport theoretical calculations, we find that the asymmetric Janus monolayer materials (HfSSe and ZrSSe) possess the thermoelectric advantages of two interfaces (S and Se) simultaneously at both room temperature and high temperatures. The interface effect will directionally enhance the thermoelectric figure of merit (ZT) of in-plane heterostructures along the direction perpendicular to the interface. In addition, the introduction of structural dislocations at the interface can significantly enhance the ZT value of the in-plane heterostructure in the transport along the direction parallel to the interface. At the same time, by adjusting the ratio of the two materials at the interface, the optimal ZT of the in-plane heterostructure along the transport direction parallel to the interface can be enhanced to 1.63 (3.4) at 300 K (800 K). Furthermore, we propose that employing laser ablation to fabricate vertical heterostructures into graphical superlattices can substantially decrease the lattice thermal conductivity of the structure, thereby enhancing the thermoelectric performance of the material significantly. Our study provides theoretical support for enhancing the thermoelectric performance of 2D materials.

The urgent demand for sustainable energy solutions has accelerated the development of rechargeable batteries, where the design of high-performance electrode materials plays a pivotal role. Since their discovery in 2011, two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, have garnered significant attention owing to their excellent electrical conductivity, high mechanical strength, tailorable surface chemistry, and large specific surface area with abundant active sites. These unique properties render MXenes highly promising for electrochemical energy storage, particularly in lithium−ion, lithium−sulfur, and lithium−oxygen batteries, as well as emerging non-lithium−ion battery systems. However, their practical implementation is hindered by critical challenges including structural restacking, poor stability, and unfavorable surface terminations. In this review, we focus on a computational perspective for the rational design and performance optimization of MXene-based electrodes. Density functional theory (DFT) calculations have yielded fundamental insights into the intrinsic properties, modification mechanisms, and electrochemical behaviors of MXenes. Additionally, machine learning has enabled high-throughput screening and predictive modeling of their structure−property relationships. More importantly, this review not only summarizes the theoretical advances in MXenes for energy storage applications but also extracts actionable theoretical insights and performance prediction principles. These efforts provide a comprehensive theoretical reference for computational studies on MXenes, allowing researchers to efficiently grasp the research landscape, core mechanisms, and modification strategies. Furthermore, this review offers targeted guidance for experimental investigations by facilitating the optimization of modification schemes, the selection of suitable battery systems, and the reduction of trial-and-error in experimental design.

We present a protocol for realizing parity detection of a bipartite system based on non-Hermitian spectral phase transition. The system comprises two superconducting qubits as information carriers and an auxiliary superconducting resonator. We derive a parity-dependent effective Hamiltonian, where the frequency of the resonator is shifted when the qubits are in even-parity states. The frequency shift results in a spectral phase transition in the non-Hermitian dynamical matrix in the Heisenberg picture, where the spectrum turns from purely imaginary to purely real. With a proper frequency shift, the spectral distinction between the even- and odd-parity cases leads to markedly different photon number dynamics, i.e., exponential growth for the odd-parity case, and bounded oscillations for the even-parity case. By measuring the photon number in the resonator after a fixed evolution time, the parity of the qubits can be reliably discriminated. Numerical simulations further demonstrate that the protocol is robust against systematic imperfections and decoherence, including the spontaneous emission and dephasing of the qubits, as well as cavity decay. These results establish a practical route to parity detection via non-Hermitian dynamics. This approach provides a scalable building block for superconducting-circuit quantum information processing.

Competing orders represent a central challenge in understanding strongly correlated systems. In this work, we employ projector quantum Monte Carlo simulations to study a sign-problem-free bilayer extended Hubbard model. In this model, a charge stripe phase, characterized by a peak at (0\pm 2\text{π}\delta ,0) is induced by highly anisotropic interlayer antiferromagnetic spin-exchange coupling J_z, and strongly suppressed by the decreasing spin-exchange anisotropy (i.e., introducing the spin-flip term J_{\mathrm{\perp }}); in contrast, the introduction of J_{\perp } favors the emergence of interlayer pairing superconductivity. We further demonstrate that the anisotropy of the interlayer spin-exchange directly governs the competition between these two phases, while the on-site interaction U plays a complex role in tuning both the charge stripe and superconductivity. Furthermore, against the background of charge stripes we discover the spin stripes, characterized by twice the period of charge stripes, indicating the profound internal connection between them. Our work identifies the key factors driving charge stripe formation, highlights the sensitivity of both the charge stripe and superconducting phases to interaction parameters, and thereby provides valuable insights into competing orders in strongly correlated systems.

Altermagnets constitute a recently identified magnetic phase that combines the absence of macroscopic magnetization, characteristic of antiferromagnets, with the spin splitting typically associated with ferromagnets. This hybrid nature enables stray-field-free spin transport and ultrafast spin dynamics, offering new opportunities for dissipationless spintronics and spin-caloritronics. Here, we perform a comprehensive symmetry analysis and advanced first-principles calculations to investigate the intrinsic spin Hall and spin Nernst effects in two-dimensional altermagnets, using bilayer MnPSe₃ as a representative example. In the nonrelativistic limit, interlayer sliding induces a d-wave-like spin splitting and generates time-reversal-odd, intraband-dominated spin Hall and spin Nernst responses. Changing the sliding direction alters the associated symmetry operations, thereby modifying the spin splitting of the Fermi surface and enabling tunable control of spin-transport properties. This modulation originates from symmetry-driven variations in the relative contributions of opposite spins. Our findings identify interlayer sliding as an effective route to tuning spin transport in altermagnets, establishing a versatile two-dimensional platform for exploring the interplay between altermagnetism and spin transport, and paving the way for future advances in altermagnetic spintronics and spin-caloritronics.

We investigate a frustrated four-spin plaquette spin-boson model with competing nearest-neighbor and diagonal Ising couplings, where each spin is coupled to an independent bosonic bath. Combining a path-integral strong-coupling analysis with variational matrix product state simulations, we obtain the ground-state phase diagram. In the strong-dissipation limit we map the model onto a classical plaquette and derive analytic phase boundaries between ferromagnetic, Néel, and stripe phases. At intermediate dissipation we find a delocalized phase and two localized ordered phases with Néel and stripe character. We show that the localized phases are separated by a first-order line, while each is connected to the delocalized regime via a continuous (second-order) localization transition, and that these three boundaries meet at a quantum triple point. Analysis of spin correlations and reduced density matrices further reveals that entanglement concentrates on nearest-neighbor (diagonal) bonds in the Néel (stripe) phase, whereas in the delocalized regime intra-plaquette two-spin entanglement is strongly suppressed in favor of enhanced spin-bath correlations.