The main goal of our study is to reveal unexpected but intriguing analogies arising between optical solitons and nuclear physics, which still remain hidden from us. We consider the main cornerstones of the concept of nonlinear optics of nuclear reactions and the well-dressed repulsive-core solitons. On the base of this model, we reveal the most intriguing properties of the nonlinear tunneling of nucleus-like solitons and the soliton self-induced sub-barrier transparency effect. We describe novel interesting and stimulating analogies between the interaction of nucleus-like solitons on the repulsive barrier and nuclear sub-barrier reactions. The main finding of this study concerns the conservation of total number of nucleons (or the baryon number) in nuclear-like soliton reactions. We show that inelastic interactions among well-dressed repulsive-core solitons arise only when a “cloud” of “dressing” spectral side-bands appears in the frequency spectra of the solitons. This property of nucleus-like solitons is directly related to the nuclear density distribution described by the dimensionless small shape-squareness parameter. Thus the Fourier spectra of nucleus-like solitons are similar to the nuclear form factors. We show that the nuclear-like reactions between well-dressed solitons are realized by “exchange” between “particle-like” side bands in their spectra.

We review the predictions of quark models for multiquark configurations that are bound or resonant states, and compare different methods for estimating the properties of resonances.

Recently, a new excited baryon state, $\varOmega(2012)$, was observed in the invariant mass spectra of $K^-\varXi^0$ and $K^0_S \varXi^-$ by the Belle collaboration. This state has a narrow width ($\sim$ $6$ MeV) compared to other baryon states with a similar mass. Here, we provide a mini-review on the $\varOmega(2012)$ state from the molecular perspective, where it appears to be a dynamically generated state with spin-parity $3/2^-$ from the coupled-channels interactions of the $\bar{K} \varXi(1530)$ and $\eta \varOmega$ in $s$-wave and $\bar{K} \varXi$ in $d$-wave. Additionally, alternative explanations for the $\varOmega(2012)$ resonance are also discussed.

Terahertz heterodyne receivers with high sensitivity and spectral resolution are crucial for various applications. Here, we present a room-temperature atomic terahertz heterodyne receiver that achieves ultrahigh sensitivity and frequency resolution. At a signal frequency of 338.7 GHz, we obtain a sensitivity of $2.88\pm0.09$ µV$\cdot$cm$^{-1}\cdot$Hz$^{-1/2}$ for electric field measurements. The calibrated linear dynamical range spans approximately 89 dB, ranging from $-110$ dBV/cm to $-21$ dBV/cm. We demodulate a 400 symbol stream encoded in 4-state phase-shift keying, demonstrating excellent phase detection capability. By scanning the frequency of the local oscillator, we realize a terahertz spectrometer with Hz level frequency resolution. This resolution is more than two orders of magnitude higher than that of existing terahertz spectrometers. The demonstrated terahertz heterodyne receiver holds promising potential for working across the entire terahertz spectrum, significantly advancing its practical applications.

Our primary objective is to mitigate the adverse effects of temperature fluctuations on the optical frequency transmission system by reducing the length of the interferometer. Following optimization, the phase-temperature coefficient of the optical system is reduced to approximately 1.35 fs/K. By applying a sophisticated temperature control to the remained “out-of-loop” optics fiber, the noise floor of the system has been effectively lowered to $10^{-21}$ level. Based on this performance-enhanced transfer system, we demonstrate coherent transmission of optical frequency through 500-km spooled fiber link. After being actively compensated, the transfer instability of $4.5\times 10^{-16}$ at the averaging time of 1 s and $5.6\times 10^{-21}$ at 10000 s is demonstrated. The frequency uncertainty of received light at remote site relative to that of the origin light at local site is achieved to be $1.15\times 10^{-19}$. This enhanced system configuration is particularly well suited for future long-distance frequency transmission and comparison of the most advanced optical clock signals.

The carbon black (CB) is introduced to manufacture CB/graphene oxide (GO) composite material to mitigate limitations of GO as a saturable absorber with the excellent performance in ultrafast fiber lasers. At a central wavelength of 1555.5 nm, the stable mode-locked pulse with width of 656 fs, repetition rate of 20.16 MHz, and high signal-to-noise ratio of 82.07 dB is experimentally obtained. Additionally, experimental observations for pulsation phenomena of vector biperiodic solitons combining period-1 and period-17, period-2 and period-32, period-3 and period-36 are verified via simulations.

The outstanding issue to overcoming atmospheric turbulence on distant imaging is a fundamental interest and technological challenge. We propose a novel scenario and technique to restore the optical image in turbulent environmental by referring to Cyclopean image with binocular vision. With human visual intelligence, image distortion resulting from the turbulence is shown to be substantially suppressed. Numerical simulation results taking into account of the atmospheric turbulence, optical image system, image sensors, display and binocular vision perception are presented to demonstrate the robustness of the image restoration, which is compared with a single channel planar optical imaging and sensing. Experiment involving binocular telescope, image recording and the stereo-image display is conducted and good agreement is obtained between the simulation with perceptive experience. A natural extension of the scenario is to enhance the capability of anti-vibration or anti-shaking for general optical imaging with Cyclopean image.

Tokamak plasmas with elongated cross sections are susceptible to vertical displacement events (VDEs), which can damage the first wall via heat flux or electromagnetic (EM) forces. We present a 3D nonlinear reduced magnetohydrodynamic (MHD) simulation of CFETR plasma during a cold VDE following the thermal quench, focusing on the relationship among the EM force, plasma displacement, and the $n=1$ mode. The dominant mode, identified as $m/n = 2/1$, becomes destabilized when most of the current is contracted within the $q = 2$ surface. The displacement of the plasma current centroid is less than that of the magnetic axis due to the presence of SOL current in the open field line region. Hence, the symmetric component of the induced vacuum vessel current is significantly mitigated. The direction of the sideways force keeps a constant phase approximately compared to the asymmetric component of the vacuum vessel current and the SOL current, which in turn keep in-phase with the dominant $2/1$ mode. Their amplitudes are also closely associated with the growth of the dominant mode. These findings provide insights into potential methods for controlling the phase and amplitude of sideways forces during VDEs in the future.

For warm/hot and dense plasmas (WDPs), ionization potential depression (IPD) plays a crucial role in determining its ionization balance and understanding the resultant microscopic plasma properties. A sophisticated and unified IPD model is necessary to resolve those existing discrepancies between theoretical and experimental results. However, the applicability of those widely used IPD models nowadays is limited, especially for the nonlocal thermodynamic equilibrium (non-LTE) dense plasma produced by short-pulse laser. In this work, we propose an IPD model that considers inelastic atomic processes, in which three-body recombination and collision ionization processes are found to play a crucial role in determining the electron distribution and IPD for a WDP. This IPD model is validated by reproducing latest experimental results of Al plasmas with a wide-range condition of 70 eV–700 eV temperature and $0.2$–$3$ times solid density, as well as a typical non-LTE system of hollow Al ions. It is demonstrated that the present IPD model has a significant temperature dependence due to the consideration of the inelastic collision processes. With a lower computational cost and wider application range of plasma conditions, the proposed model is expected to provide a promising tool to study the ionization balance and the atomic processes, as well as the related radiation and particle transports properties of the WDP.

We study the desorption mechanism of hydrogen isotopes from graphene surface using first-principles calculations, with focus on the effects of quantum tunneling. At low temperatures, quantum tunneling plays a dominant role in the desorption process of both hydrogen monomers and dimers. In the case of dimer desorption, two types of mechanisms, namely the traditional one-step desorption in the form of molecules (molecular mechanism), and the two-step desorption in the form of individual atoms (atomic mechanism), are studied and compared. For the ortho-dimers, the dominant desorption mechanism is found to switch from the molecular mechanism to the atomic mechanism above a critical temperature, which is $\sim$ 300 K and 200 K for H and D, respectively.

Based on the Gross–Pitaevskii equation, we theoretically investigate exciton Bose–Einstein condensation (BEC) in transition metal dichalcogenide monolayers (TMDC-MLs) under in-plane magnetic fields. We observe that the in-plane magnetic fields exert a strong influence on the exciton BEC wave functions in TMDC-MLs because of the mixing of the bright and dark exciton states via Zeeman effect. This leads to the brightening of the dark exciton BEC states. The competition between the dipole–dipole interactions caused by the long-range Coulomb interaction and the Zeeman effect induced by the in-plane magnetic fields can effectively regulate dark exciton BEC states. Our findings emphasize the utility of TMD-MLs as platforms for investigating collective phenomenon involving excited states.

Recently, high temperature ($T_{\rm c}\approx 80$ K) superconductivity (SC) has been discovered in La$_3$Ni$_2$O$_7$ (LNO) under pressure. This raises the question of whether the superconducting transition temperature $T_{\rm c}$ could be further enhanced under suitable conditions. One possible route for achieving higher $T_{\rm c}$ is element substitution. Similar SC could appear in the $Fmmm$ phase of rare-earth (RE) R$_3$Ni$_2$O$_7$ (RNO, R = RE element) material series under suitable pressure. The electronic properties in the RNO materials are dominated by the Ni $3d$ orbitals in the bilayer NiO$_2$ plane. In the strong coupling limit, the SC could be fully characterized by a bilayer single $3d_{x^2-y^2}$-orbital $t$–$J_{\parallel}$–$J_{\perp}$ model. With RE element substitution from La to other RE element, the lattice constant of the $Fmmm$ RNO material decreases, and the resultant electronic hopping integral increases, leading to stronger superexchanges between the $3d_{x^2-y^2}$ orbitals. Based on the slave-boson mean-field theory, we explore the pairing nature and the evolution of $T_{\rm c}$ in RNO materials under pressure. Consequently, it is found that the element substitution does not alter the pairing nature, i.e., the inter-layer s-wave pairing is always favored in the superconducting RNO under pressure. However, the $T_{\rm c}$ increases from La to Sm, and a nearly doubled $T_{\rm c}$ could be realized in SmNO under pressure. This work provides evidence for possible higher $T_{\rm c}$ R$_3$Ni$_2$O$_7$ materials, which may be realized in further experiments.

High-temperature superconductivity (HTSC) remains one of the most challenging and fascinating mysteries in condensed matter physics. Recently, superconductivity with transition temperature exceeding liquid-nitrogen temperature is discovered in La$_{3}$Ni$_{2}$O$_{7}$ at high pressure, which provides a new platform to explore the unconventional HTSC. In this work, using high-resolution angle-resolved photoemission spectroscopy and ab initio calculation, we systematically investigate the electronic structures of La$_{3}$Ni$_{2}$O$_{7}$ at ambient pressure. Our experiments are in nice agreement with ab initio calculations after considering an orbital-dependent band renormalization effect. The strong electron correlation effect pushes a flat band of $d_{z^{2}}$ orbital component below the Fermi level ($E_{\rm F}$), which is predicted to locate right at $E_{\rm F}$ under high pressure. Moreover, the $d_{x^{2}-y^{2}}$ band shows pseudogap-like behavior with suppressed spectral weight and diminished quasiparticle peak near $E_{\rm F}$. Our findings provide important insights into the electronic structure of La$_{3}$Ni$_{2}$O$_{7}$, which will shed light on understanding of the unconventional superconductivity in nickelates.

The discovery of ferroelectricity in HfO$_{2}$-based materials with high dielectric constant has inspired tremendous research interest for next-generation electronic devices. Importantly, films structure and strain are key factors in exploration of ferroelectricity in fluorite-type oxide HfO$_{2}$ films. Here we investigate the structures and strain-induced ferroelectric transition in different phases of few-layer HfO$_{2}$ films (layer number $N=1$–5). It is found that HfO$_{2}$ films for all phases are more stable with increasing films thickness. Among them, the $Pmn2_{1}$ (110)-oriented film is most stable, and the films of $N=4$, 5 occur with a $P2_{1}$ ferroelectric transition under tensile strain, resulting in polarization about 11.8 µC/cm$^{2}$ along in-plane $a$-axis. The ferroelectric transition is caused by the strain, which induces the displacement of Hf and O atoms on the surface to non-centrosymmetric positions away from the original paraelectric positions, accompanied by the change of surface Hf–O bond lengths. More importantly, three new stable HfO$_{2}$ 2D structures are discovered, together with analyses of computed electronic structures, mechanical, and dielectric properties. This work provides guidance for theoretical and experimental study of the new structures and strain-tuned ferroelectricity in freestanding HfO$_{2}$ films.

The rapid advancement in electric vehicles and electrochemical energy storage technology has raised the demands placed on rechargeable batteries. It is essential to comprehend the operational principles and degradation mechanisms of batteries across multiple scales to propel the research on rechargeable batteries for the next generation forward. Microstructure, phase information, and lattice of energy materials in both two dimensions and three dimensions can be intuitively obtained through the utilization of x-ray imaging techniques. Additionally, x-ray imaging technology is increasingly gaining attention due to its non-destructive nature and high penetrative capability, enabling in situ experiments and multi-scale spatial resolution. In this review, we initially overview the basic principles and characteristics of several key x-ray imaging technologies. Each x-ray imaging technology is tailored to specific application scenarios. Furthermore, examples of multi-scale implementations of x-ray imaging technologies in the field of rechargeable batteries are discussed. This review is anticipated to augment the comprehension of readers for x-ray imaging techniques as well as to stimulate the development of novel concepts and approaches in rechargeable battery research.

About 2 percent of red clump stars are found to be the lithium-rich and thus the surface lithium increases obviously in some red clump stars. The physical mechanism of the lithium enrichment in these stars has not yet been explained satisfactorily by the evolutionary models of single stars. The flash induced internal gravity wave mixing (i.e., IGW) could play a primary role in explaining the red clump star with lithium enrichment and it has a very significant impact on the internal structure and surface compositions of a star. Rotation can significantly increase the mixing efficiency of the internal gravity wave because the timescale for the enrichment event has been enlarged. Thermohaline mixing can explain the observed behavior of lithium on red giant stars that are more luminosity than the RGB bump. However, it has a very small effect on the diffusion of elements because its diffusion coefficient is much smaller than the one of IGW induced mixing after the core helium flash.