理论物理通讯致力于报告理论物理领域的重要新发展。论文涵盖领域：数学物理量子物理与量子信息粒子物理与量子场论核物理万有引力理论、天体物理与宇宙学原子、分子、光学（AMO）与等离子体物理、化学物理统计物理、软物质与生物物理凝聚态理论其他某些新的跨学科学科也被纳入.

Communications in Theoretical Physics is dedicated to reporting significant new developments in the field of theoretical physics. The journal covers areas including: mathematical physics, quantum physics and quantum information, particle physics and quantum field theory, nuclear physics, gravitational theory, astrophysics and cosmology, atomic, molecular, and optical (AMO) physics, plasma physics, chemical physics, statistical physics, soft matter and biophysics, condensed matter theory, as well as other emerging interdisciplinary fields.

《Communications in Theoretical Physics》致力于报告理论物理领域的重要新进展。论文涵盖的领域包括：数学物理、量子物理与量子信息、粒子物理与量子场论、核物理、万有引力理论、天体物理与宇宙学、原子、分子、光学（AMO）与等离子体物理、化学物理、统计物理、软物质与生物物理、凝聚态理论，以及其他一些新的跨学科领域。

Communications in Theoretical Physics

Abstract Partial differential equations (PDEs) are important tools for scientific research and are widely used in various fields. However, it is usually very difficult to obtain accurate analytical solutions of PDEs, and numerical methods to solve PDEs are often computationally intensive and very time-consuming. In recent years, Physics Informed Neural Networks (PINNs) have been successfully applied to find numerical solutions of PDEs and have shown great potential. All the while, solitary waves have been of great interest to researchers in the field of nonlinear science. In this paper, we perform numerical simulations of solitary wave solutions of several PDEs using improved PINNs. The improved PINNs not only incorporate constraints on the control equations to ensure the interpretability of the prediction results, which is important for physical field simulations, in addition, an adaptive activation function is introduced. By introducing hyperparameters in the activation function to change the slope of the activation function to avoid the disappearance of the gradient, computing time is saved thereby speeding up training. In this paper, the mKdV equation, the improved Boussinesq equation, the Caudrey–Dodd–Gibbon–Sawada–Kotera equation and the p-gBKP equation are selected for study, and the errors of the simulation results are analyzed to assess the accuracy of the predicted solitary wave solution. The experimental results show that the improved PINNs are significantly better than the traditional PINNs with shorter training time but more accurate prediction results. The improved PINNs improve the training speed by more than 1.5 times compared with the traditional PINNs, while maintaining the prediction error less than 10 −2 in this order of magnitude.

Yanan Guo

Xiaoqun Cao

Kecheng Peng

Solving nonlinear soliton equations using improved physics-informed neural networks with adaptive mechanisms

使用具有自适应机制的改进物理信息神经网络求解非线性孤子方程

By imposing the boundary condition associated with the boundary structure of the null boundaries rather than the usual one, we find for Einstein's gravity that the variational principle works only in its submanifold with the null boundaries given by the expansion-free and shear-free hypersurfaces rather than in the whole covariant phase space. This implies that the key requirement in Harlow–Wu's algorithm for the timelike boundaries is too restrictive for the null ones. To incorporate more generic situations into Harlow–Wu's algorithm, we relax such a requirement. As a result, we successfully reproduce the Hamiltonian obtained previously by Wald–Zoupas' prescription for Einstein's gravity.

Kai Shi

Xuan Wang

Yihong Xiu

Hongbao Zhang

Commun. Theor. Phys.

Covariant phase space with null boundaries

协变相空间与零边界

Dimension-dependent giant density fluctuations are a typical feature of active matter systems. In this work, we study the density fluctuation in two-dimensional mixtures of active and passive particles by Brownian dynamics simulations. The boundary of motility-induced phase separation is determined by the transition from unimodal to bimodal density distribution. A rapid increase of the fluctuation exponent near the boundary of phase separation in the plane of density and Péclet number was observed. When phase separation occurs, the fluctuation exponent is an approximate constant of0.85.

Jian Zhang

Tao Huang

Guoqing Xu

Yong Chen

Density fluctuations of two-dimensional active-passive mixtures

二维活性-被动混合物的密度涨落

Abstract In this paper, the N-soliton solutions for massive Thirring model (MTM) in the laboratory coordinates are analyzed via the Riemann-Hilbert approach. The direct scattering including the analyticity, symmetries and asymptotic behaviors of the Jost solutions as |λ| → ∞ and λ → 0 are given. Considering that the scattering coefficients have simple zeros, the matrix Riemann-Hilbert problem, reconstruction formulas and corresponding trace formulas are also derived. Further, the N-soliton solutions in the reflectionless case are obtained explicitly in the form of determinants. The propagation characteristics of one-soliton solutions and interaction properties of two-soliton solutions are discussed. In particular, the asymptotic expressions of two-soliton solutions as |t| → ∞ are obtained, which show that the velocities and amplitudes of the asymptotic solitons don’t change before and after interaction except the position shifts. In addition, three types of bounded states for two-soliton solutions are presented with certain parametric conditions.

Yuan Li

Min Li

Tao Xu

Ye-Hui Huang

Chuan-Xin Xu

N-soliton solutions and asymptotic analysis for the massive Thirring model in the laboratory coordinates via the Riemann-Hilbert approach

通过Riemann-Hilbert方法研究实验室坐标系下大质量Thirring模型的N-孤子解及渐近分析

Abstract The β -decay properties of 67−80 As nuclei have been investigated within the framework of the proton–neutron quasi-particle random phase approximation (pn-QRPA) model. The nuclear deformation obtained from the finite range droplet model is used as an input parameter in the pn-QRPA model for the analysis of β -decay properties including Gamow–Teller strength distributions, log ft , β -decay half-lives and stellar β ± decay rates. The predicted log ft values were fairly consistent with the observed data. The computed β -decay half-lives matched the measured values by a factor of 10. The stellar rates were compared with the shell model outcomes. At high densities and temperatures, the β + and electron capture rates had a finite contribution. However, the β − and positron capture rates are only significant at high temperatures and low densities. The pn-QRPA rates outperformed the shell model rates by a factor of 22 or more.

Abdul Kabir

Jameel-Un Nabi

Wajeeha Khalid

Hamad Almujibah

Re-examination of the β-decay properties of As isotopes

砷同位素β衰变性质的再研究

Abstract In this paper, we investigate the quantum coherence extraction between two accelerating Unruh-DeWitt detectors, coupling to a scalar field in (3+1)-dimensional Minkowski spacetime. We find that quantum coherence as a nonclassical correlation can be generated through the Markovian evolution of the detector system, just like quantum entanglement. However, with growing Unruh temperature, in contrast to monotonously degrading entanglement, we find that quantum coherence exhibits a striking revival phenomenon. For certain detectors' initial state choices, the coherence measure will reduce to zero at first and then grow to an asymptotic value. We verify such coherence revival by inspecting its metrological advantage on the quantum Fisher information (QFI) enhancement. Since the maximal QFI bounds the accuracy of quantum parameter estimation, we conclude that the extracted coherence can be utilized as a physical resource in quantum metrology.

Jiafan Wang

Jingjun Zhang

Jun Feng

Coherence revival under the Unruh effect and its metrological advantage

Unruh效应下的相干性恢复及其计量学优势

Abstract A classification of multipartite entanglement is introduced for pure and mixed states. The classification is based on the distribution of entanglement between the qubits of a given system, with a mathematical framework used to characterize fully entangled states. Then we use current machine learning and deep learning techniques to automatically classify a random state of two, three, and four qubits without the need to compute the amount of the different types of entanglement in each run; rather this is done only in the learning process. The technique shows high, near-perfect, accuracy in the case of pure states. As expected, this accuracy drops, more or less, when dealing with mixed states and when increasing the number of parties involved.

Fadwa EL AYACHI

Hicham AIT MANSOUR

Morad EL BAZ

Classification of Entanglement Distribution Using Machine Learning

使用机器学习进行纠缠分布的分类

Abstract Conversion between different types of entangled states is an interesting problem in quantum mechanics. But research on the conversion between Greenberger-Horne-Zeilinger (GHZ) state and Knill-Laflamme-Milburn (KLM) state in atomic system has not been reported. In this paper, we propose a scheme to realize the interconversion (one-step) between GHZ state and KLM state with Rydberg atoms. By utilizing Rydberg-mediated interactions, we simplify the system. By combining Lie-transform-based pulse design, the evolution path is built up to realize interconversion of GHZ state and KLM state. The numerical simulation result shows that the present scheme is robust against decoherence and operational imperfection.

J. P. Wang

Yanqiang Ji

L. P. Yang

C. Q. Wang

L. Dong

X. M. Xiu

Deterministic interconversion of GHZ state and KLM state via Lie-transform-based pulse design in Rydberg atoms

通过基于李变换的脉冲设计在里德堡原子中实现GHZ态与KLM态的确定性相互转换

Abstract The propagation properties of ion-acoustic solitary and shock waves in the magnetized viscous plasma with nonthermal trapped electrons are investigated. The Cairns-Gurevich distribution as the electron distribution is considered to describe the plasma nonthermality and particle trapping. By adopting the reductive perturbation technique, we derived the nonlinear Schamel-Korteweg–de Vries-Burgers (SKdVB) equation, and then obtained the ion-acoustic shock and solitary wave solutions of the SKdVB equation for different limiting cases. It is found that the impact of nonthermal parameter α, external magnetic field Ω, obliqueness lz, wave speed U0, and the ion kinematic viscosity η0 can significantly change the characteristics of the shock and solitary waves. These results may be useful for better understanding the propagation of nonlinear structures in space and laboratory plasma with nonthermal trapped electrons.

rui huo

Jiu-Lin Du

Ion-acoustic Shock and Solitary Waves in Magnetized Plasma with Cairns-Gurevich Distribution Electrons

磁化等离子体中具有Cairns-Gurevich分布电子的离子声冲击波和孤立波

Abbreviation	Commun. Theor. Phys.
Journal Impact	2.20
Quartiles(Global)	PHYSICS, MULTIDISCIPLINARY(Q2)

ISSN	0253-6102, 1572-9494
h-index	64

Publication Information	Publisher: IOP Publishing Ltd.，Publishing cycle: Monthly，Journal Type: journal，Open Access Journals: No
Basic data	Year of publication: 1996，Proportion of original research papers: 95.98%，Self Citation Rate:4.20%， Gold OA Rate: 0.00%
Average review cycle	网友分享经验：平均4.2个月
Average recruitment ratio	网友分享经验：50%

Communications in Theoretical Physics

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Solving nonlinear soliton equations using improved physics-informed neural networks with adaptive mechanisms

Covariant phase space with null boundaries

Density fluctuations of two-dimensional active-passive mixtures

N-soliton solutions and asymptotic analysis for the massive Thirring model in the laboratory coordinates via the Riemann-Hilbert approach

Re-examination of the β-decay properties of As isotopes

N-soliton solutions and asymptotic analysis for the massive Thirring model in the laboratory coordinates via the Riemann-Hilbert approach

Coherence revival under the Unruh effect and its metrological advantage

Classification of Entanglement Distribution Using Machine Learning

Deterministic interconversion of GHZ state and KLM state via Lie-transform-based pulse design in Rydberg atoms

Ion-acoustic Shock and Solitary Waves in Magnetized Plasma with Cairns-Gurevich Distribution Electrons