Communications in Theoretical Physics最新文献

Riemann–Hilbert approach and soliton solutions for the Lakshmanan–Porsezian–Daniel equation with nonzero boundary conditions 具有非零边界条件的拉克什曼-波尔舍-丹尼尔方程的黎曼-希尔伯特方法和孤子解

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-09-12 DOI: 10.1088/1572-9494/ad6b1c

Yilin Wang and Biao Li

引用次数: 0

Towards an efficient variational quantum algorithm for solving linear equations 实现求解线性方程的高效变分量子算法

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-09-09 DOI: 10.1088/1572-9494/ad597d

WenShan Xu, Ri-Gui Zhou, YaoChong Li and XiaoXue Zhang

{"title":"Towards an efficient variational quantum algorithm for solving linear equations","authors":"WenShan Xu, Ri-Gui Zhou, YaoChong Li and XiaoXue Zhang","doi":"10.1088/1572-9494/ad597d","DOIUrl":"https://doi.org/10.1088/1572-9494/ad597d","url":null,"abstract":"Variational quantum algorithms are promising methods with the greatest potential to achieve quantum advantage, widely employed in the era of noisy intermediate-scale quantum computing. This study presents an advanced variational hybrid algorithm (EVQLSE) that leverages both quantum and classical computing paradigms to address the solution of linear equation systems. Initially, an innovative loss function is proposed, drawing inspiration from the similarity measure between two quantum states. This function exhibits a substantial improvement in computational complexity when benchmarked against the variational quantum linear solver. Subsequently, a specialized parameterized quantum circuit structure is presented for small-scale linear systems, which exhibits powerful expressive capabilities. Through rigorous numerical analysis, the expressiveness of this circuit structure is quantitatively assessed using a variational quantum regression algorithm, and it obtained the best score compared to the others. Moreover, the expansion in system size is accompanied by an increase in the number of parameters, placing considerable strain on the training process for the algorithm. To address this challenge, an optimization strategy known as quantum parameter sharing is introduced, which proficiently minimizes parameter volume while adhering to exacting precision standards. Finally, EVQLSE is successfully implemented on a quantum computing platform provided by IBM for the resolution of large-scale problems characterized by a dimensionality of 220.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

N = 2 a = 1 supersymmetric KdV equation and its Darboux–Bäcklund transformations N = 2 a = 1 超对称 KdV 方程及其达尔布-贝克伦变换

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-09-04 DOI: 10.1088/1572-9494/ad6a04

XiaoXia Yang, Lingling Xue, Q P Liu

引用次数: 0

Path integral formalism of open quantum systems with non-diagonal system-bath coupling 具有非对角系统-浴耦合的开放量子系统的路径积分形式主义

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-09-04 DOI: 10.1088/1572-9494/ad696b

Ruofan Chen

引用次数: 0

Simulation study of multi-layer titanium nitride nanodisk broadband solar absorber and thermal emitter 多层氮化钛纳米盘宽带太阳能吸收器和热辐射器的模拟研究

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-09-03 DOI: 10.1088/1572-9494/ad6852

Xi Huang, Yingting Yi, Qianju Song, Zao Yi, Can Ma, Chaojun Tang, Qingdong Zeng, Shubo Cheng, Rizwan Raza

{"title":"Simulation study of multi-layer titanium nitride nanodisk broadband solar absorber and thermal emitter","authors":"Xi Huang, Yingting Yi, Qianju Song, Zao Yi, Can Ma, Chaojun Tang, Qingdong Zeng, Shubo Cheng, Rizwan Raza","doi":"10.1088/1572-9494/ad6852","DOIUrl":"https://doi.org/10.1088/1572-9494/ad6852","url":null,"abstract":"Solar energy has always been a kind of energy with large reserves and wide application. It is well utilized through solar absorbers. In our study, the finite difference time domain method (FDTD) is used to simulate the absorber composed of refractory metal materials, and its absorption performance and thermal emission performance are obtained. The ultra-wide band of 200 nm–3000 nm reaches 95.93% absorption efficiency, of which the bandwidth absorption efficiency of 2533 nm (200 nm–2733 nm) is greater than 90%. The absorption efficiency in the whole spectrum range (200 nm–2733 nm) is 97.17% on average. The multilayer nanodisk structure of the absorber allows it to undergo strong surface plasmon resonance and near-field coupling when irradiated by incident light. The thermal emission performance of the absorber enables it to also be applied to the thermal emitter. The thermal emission efficiency of 95.37% can be achieved at a high temperature of up to 1500 K. Moreover, the changes of polarization and incident angle do not cause significant changes in absorption. Under the gradual change of polarization angle (0°–90°), the absorption spectrum maintains a high degree of consistency. As the incident angle increases from 0° to 60°, there is still 85% absorption efficiency. The high absorption efficiency and excellent thermal radiation intensity of ultra-wideband enable it to be deeply used in energy absorption and conversion applications.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Scalar dark energy models and scalar–tensor gravity: theoretical explanations for the accelerated expansion of the present Universe 标量暗能量模型和标量张量引力：当前宇宙加速膨胀的理论解释

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-08-21 DOI: 10.1088/1572-9494/ad5aeb

Peixiang Ji, Lijing Shao

{"title":"Scalar dark energy models and scalar–tensor gravity: theoretical explanations for the accelerated expansion of the present Universe","authors":"Peixiang Ji, Lijing Shao","doi":"10.1088/1572-9494/ad5aeb","DOIUrl":"https://doi.org/10.1088/1572-9494/ad5aeb","url":null,"abstract":"The reason for the present accelerated expansion of the Universe stands as one of the most profound questions in the realm of science, with deep connections to both cosmology and fundamental physics. From a cosmological point of view, physical models aimed at elucidating the observed expansion can be categorized into two major classes: dark energy and modified gravity. We review various major approaches that employ a single scalar field to account for the accelerating phase of our present Universe. Dynamic system analysis was employed in several important models to find cosmological solutions that exhibit an accelerating phase as an attractor. For scalar field models of dark energy, we consistently focused on addressing challenges related to the fine-tuning and coincidence problems in cosmology, as well as exploring potential solutions to them. For scalar–tensor theories and their generalizations, we emphasize the importance of constraints on theoretical parameters to ensure overall consistency with experimental tests. Models or theories that could potentially explain the Hubble tension are also emphasized throughout this review.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Weak gravitational lensing around dyonic ModMax black hole in plasma 等离子体中镝莫德马克斯黑洞周围的弱引力透镜效应

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-08-21 DOI: 10.1088/1572-9494/ad6853

Ziyodulla Turakhonov, Farruh Atamurotov, Ali Övgün, Ahmadjon Abdujabbarov, Sunnatillo Urinov

引用次数: 0

A gas sensing neural circuit for an olfactory neuron 嗅觉神经元的气体感应神经回路

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-08-21 DOI: 10.1088/1572-9494/ad595d

Xi-Kui Hu, Song Zhu, Juan Yang, Zhao Yao, Ping Zhou, Jun Ma

{"title":"A gas sensing neural circuit for an olfactory neuron","authors":"Xi-Kui Hu, Song Zhu, Juan Yang, Zhao Yao, Ping Zhou, Jun Ma","doi":"10.1088/1572-9494/ad595d","DOIUrl":"https://doi.org/10.1088/1572-9494/ad595d","url":null,"abstract":"A gas sensor can convert external gas concentration or species into electric voltage or current signals by physical adsorption or chemical changes. As a result, a gas sensor in a nonlinear circuit can be used as a sensitive sensor for detecting external gas signals from the olfactory system. In this paper, a gas sensor and a field-effect transistor are incorporated into a simple FithzHugh–Nagumo neural circuit for capturing and encoding external gas signals. An improved functional neural circuit is obtained, and the effect of gas concentration, gas species and neuronal activity can be discerned as the gate voltage, threshold voltage and activation coefficient of the field-effect transistor, respectively. The gas concentration can affect the neural activities from quiescent to normal working and, finally, to saturation state in bursting, spiking, periodic and chaotic firings with different frequencies. The effects of gas species and neuronal activity on the firing state can also be achieved in this functional neural circuit. In addition, variations in the gate voltage, threshold voltage and activation coefficient can cause switching between different firing modes. These results can be helpful in designing artificial olfactory devices for bionic gas recognition and other coupled systems arising in applied sciences.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study for obtaining the exact solutions for the propagation of pulses in optical fibers 研究如何获得脉冲在光纤中传播的精确解

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-08-16 DOI: 10.1088/1572-9494/ad526c

Arzu Akbulut, Waseem Razzaq, Filiz Tascan

引用次数: 0

Constraining the variable generalized Chaplygin gas model in matter creation cosmology 约束物质创造宇宙学中的可变广义查普利金气体模型

IF 3.1 3区物理与天体物理

Communications in Theoretical Physics Pub Date : 2024-08-16 DOI: 10.1088/1572-9494/ad58c2

Yogesh Bhardwaj, C P Singh

{"title":"Constraining the variable generalized Chaplygin gas model in matter creation cosmology","authors":"Yogesh Bhardwaj, C P Singh","doi":"10.1088/1572-9494/ad58c2","DOIUrl":"https://doi.org/10.1088/1572-9494/ad58c2","url":null,"abstract":"We explore the variable generalized Chaplygin gas (VGCG) model in the theory of matter creation cosmology within the framework of a spatially homogeneous and isotropic flat Friedmann—Lemaître—Robertson—Walker space-time. Matter creation cosmology is based on reinterpretation of the energy–momentum tensor in Einstein’s field equations. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. The variable Chaplygin gas (VCG) is also studied as a particular solution. We use the Markov chain Monte Carlo method to constrain the free parameters of three models, namely, Lambda-Cold-Dark matter (ΛCDM), VGCG and VCG models with and without matter creation from the latest observational data from baryon acoustic oscillations, cosmic chronometer, type Ia supernovae (Pantheon) including gamma-ray bursts, quasars and the local measurement of <italic toggle=\"yes\">H</italic>\u0000<sub>0</sub> from R21 data. Two different combinations of dataset provide a fairly tight constraint on the parameters of the ΛCDM, VGCG and VCG models. The present values of various cosmological parameters are obtained, which are very close to the ΛCDM model. Furthermore, we perform stability analysis, Bayesian evidence analysis and information criteria analysis for these models through studying the sound speed, Bayes factor, and Akaike information criteria (AIC) and Bayesian information criteria (BIC) selection criteria. The values of sound speed for VGCG and VCG models shows that both the models are stable. According to AIC, it is observed that VGCG and VCG models with matter creation are supported considerably less by current observations, while BIC shows that these models are not favoured by observational data.","PeriodicalId":10641,"journal":{"name":"Communications in Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0