Frontiers of Physics最新文献_第7页

Self organizing optimization and phase transition in reinforcement learning minority game system 强化学习少数民族游戏系统中的自组织优化和阶段转换

IF 6.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-24 DOI: 10.1007/s11467-023-1378-z

Si-Ping Zhang, Jia-Qi Dong, Hui-Yu Zhang, Yi-Xuan Lü, Jue Wang, Zi-Gang Huang

{"title":"Self organizing optimization and phase transition in reinforcement learning minority game system","authors":"Si-Ping Zhang, Jia-Qi Dong, Hui-Yu Zhang, Yi-Xuan Lü, Jue Wang, Zi-Gang Huang","doi":"10.1007/s11467-023-1378-z","DOIUrl":"10.1007/s11467-023-1378-z","url":null,"abstract":"<div><p>Whether the complex game system composed of a large number of artificial intelligence (AI) agents empowered with reinforcement learning can produce extremely favorable collective behaviors just through the way of agent self-exploration is a matter of practical importance. In this paper, we address this question by combining the typical theoretical model of resource allocation system, the minority game model, with reinforcement learning. Each individual participating in the game is set to have a certain degree of intelligence based on reinforcement learning algorithm. In particular, we demonstrate that as AI agents gradually becomes familiar with the unknown environment and tries to provide optimal actions to maximize payoff, the whole system continues to approach the optimal state under certain parameter combinations, herding is effectively suppressed by an oscillating collective behavior which is a self-organizing pattern without any external interference. An interesting phenomenon is that a first-order phase transition is revealed based on some numerical results in our multi-agents system with reinforcement learning. In order to further understand the dynamic behavior of agent learning, we define and analyze the conversion path of belief mode, and find that the self-organizing condensation of belief modes appeared for the given trial and error rates in the AI system. Finally, we provide a detection method for period-two oscillation collective pattern emergence based on the Kullback–Leibler divergence and give the parameter position where the period-two appears.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 4","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139558723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Unravelling-based (auto)control of back-action in atomic Bose–Einstein condensate 原子玻色-爱因斯坦凝聚态中基于解析的反作用（自动）控制

IF 6.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-24 DOI: 10.1007/s11467-023-1375-2

V. A. Tomilin, L. V. Il’ichov

引用次数: 0

Intertype superconductivity evoked by the interplay of disorder and multiple bands 无序和多带相互作用引发的类型间超导电性

IF 6.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-24 DOI: 10.1007/s11467-023-1379-y

P. M. Marychev, A. A. Shanenko, A. V. Vagov

引用次数: 0

Two-dimensional localized modes in nonlinear systems with linear nonlocality and moiré lattices 非线性系统中的二维局部模式与线性非位置性和摩尔纹格

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-12 DOI: 10.1007/s11467-023-1370-7

Xiuye Liu, Jianhua Zeng

{"title":"Two-dimensional localized modes in nonlinear systems with linear nonlocality and moiré lattices","authors":"Xiuye Liu, Jianhua Zeng","doi":"10.1007/s11467-023-1370-7","DOIUrl":"10.1007/s11467-023-1370-7","url":null,"abstract":"<div><p>Periodic structures structured as photonic crystals and optical lattices are fascinating for nonlinear waves engineering in the optics and ultracold atoms communities. Moiré photonic and optical lattices — two-dimensional twisted patterns lie somewhere in between perfect periodic structures and aperiodic ones — are a new emerging investigative tool for studying nonlinear localized waves of diverse types. Herein, a theory of two-dimensional spatial localization in nonlinear periodic systems with fractional-order diffraction (linear nonlocality) and moiré optical lattices is investigated. Specifically, the flat-band feature is well preserved in shallow moiré optical lattices which, interact with the defocusing nonlinearity of the media, can support fundamental gap solitons, bound states composed of several fundamental solitons, and topological states (gap vortices) with vortex charge <i>s</i> = 1 and 2, all populated inside the finite gaps of the linear Bloch-wave spectrum. Employing the linear-stability analysis and direct perturbed simulations, the stability and instability properties of all the localized gap modes are surveyed, highlighting a wide stability region within the first gap and a limited one (to the central part) for the third gap. The findings enable insightful studies of highly localized gap modes in linear nonlocality (fractional) physical systems with shallow moiré patterns that exhibit extremely flat bands.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 4","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139434891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Spin transport of half-metal Mn2X3 with high Curie temperature: An ideal giant magnetoresistance device from electrical and thermal drives 具有高居里温度的半金属 Mn2X3 的自旋传输：从电热驱动看理想的巨磁电阻装置

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-05 DOI: 10.1007/s11467-023-1367-2

Bin Liu, Xiaolin Zhang, Jingxian Xiong, Xiuyang Pang, Sheng Liu, Zixin Yang, Qiang Yu, Honggen Li, Sicong Zhu, Jian Wu

{"title":"Spin transport of half-metal Mn2X3 with high Curie temperature: An ideal giant magnetoresistance device from electrical and thermal drives","authors":"Bin Liu, Xiaolin Zhang, Jingxian Xiong, Xiuyang Pang, Sheng Liu, Zixin Yang, Qiang Yu, Honggen Li, Sicong Zhu, Jian Wu","doi":"10.1007/s11467-023-1367-2","DOIUrl":"10.1007/s11467-023-1367-2","url":null,"abstract":"<div><p>Currently, magnetic storage devices are encountering the problem of achieving lightweight and high integration in mobile computing devices during the information age. As a result, there is a growing urgency for two-dimensional half-metallic materials with a high Curie temperature (<i>T</i><sub>C</sub>). This study presents a theoretical investigation of the fundamental electromagnetic properties of the monolayer hexagonal lattice of Mn<sub>2</sub>X<sub>3</sub> (X = S, Se, Te). Additionally, the potential application of Mn<sub>2</sub>X<sub>3</sub> as magneto-resistive components is explored. All three of them fall into the category of ferromagnetic half-metals. In particular, the Monte Carlo simulations indicate that the <i>T</i><sub>C</sub> of Mn<sub>2</sub>S<sub>3</sub> reachs 381 K, noticeably greater than room temperature. These findings present notable advantages for the application of Mn<sub>2</sub>S<sub>3</sub> in spintronic devices. Hence, a prominent spin filtering effect is apparent when employing non-equilibrium Green’s function simulations to examine the transport parameters. The resulting current magnitude is approximately 2 × 10<sup>4</sup> nA, while the peak gigantic magnetoresistance exhibits a substantial value of 8.36 × 10<sup>16</sup> %. It is noteworthy that the device demonstrates a substantial spin Seebeck effect when the temperature differential between the electrodes is modified. In brief, Mn<sub>2</sub>X<sub>3</sub> exhibits outstanding features as a high <i>T</i><sub>C</sub> half-metal, exhibiting exceptional capabilities in electrical and thermal drives spin transport. Therefore, it holds great potential for usage in spintronics applications.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 4","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139105482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Efficient conversion of acoustic vortex using extremely anisotropic metasurface 利用各向异性极强的元表面高效转换声涡旋

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-05 DOI: 10.1007/s11467-023-1371-6

Zhanlei Hao, Haojie Chen, Yuhang Yin, Cheng-Wei Qiu, Shan Zhu, Huanyang Chen

{"title":"Efficient conversion of acoustic vortex using extremely anisotropic metasurface","authors":"Zhanlei Hao, Haojie Chen, Yuhang Yin, Cheng-Wei Qiu, Shan Zhu, Huanyang Chen","doi":"10.1007/s11467-023-1371-6","DOIUrl":"10.1007/s11467-023-1371-6","url":null,"abstract":"<div><p>Vortex wave and plane wave, as two most fundamental forms of wave propagation, are widely applied in various research fields. However, there is currently a lack of basic mechanism to enable arbitrary conversion between them. In this paper, we propose a new paradigm of extremely anisotropic acoustic metasurface (AM) to achieve the efficient conversion from 2D vortex waves with arbitrary orbital angular momentum (OAM) to plane waves. The underlying physics of this conversion process is ensured by the symmetry shift of AM medium parameters and the directional compensation of phase. Moreover, this novel phenomenon is further verified by analytical calculations, numerical demonstrations, and acoustic experiments, and the deflection angle and direction of the converted plane waves are qualitatively and quantitatively confirmed by a simple formula. Our work provides new possibilities for arbitrary manipulation of acoustic vortex, and holds potential applications in acoustic communication and OAM-based devices.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 4","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139109763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Room-temperature ferroelectricity in van der Waals SnP2S6 范德华 SnP2S6 的室温铁电性

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-05 DOI: 10.1007/s11467-023-1369-0

Chaowei He, Jiantian Zhang, Li Gong, Peng Yu

{"title":"Room-temperature ferroelectricity in van der Waals SnP2S6","authors":"Chaowei He, Jiantian Zhang, Li Gong, Peng Yu","doi":"10.1007/s11467-023-1369-0","DOIUrl":"10.1007/s11467-023-1369-0","url":null,"abstract":"<div><p>Two-dimensional (2D) ferroelectric materials, which possess electrically switchable spontaneous polarization and can be easily integrated with semiconductor technologies, is of utmost importance in the advancement of high-integration low-power nanoelectronics. Despite the experimental discovery of certain 2D ferroelectric materials such as CuInP<sub>2</sub>S<sub>6</sub> and In<sub>2</sub>Se<sub>3</sub>, achieving stable ferroelectricity at room temperature in these materials continues to present a significant challenge. Herein, stable ferroelectric order at room temperature in the 2D limit is demonstrated in van der Waals SnP<sub>2</sub>S<sub>6</sub> atom layers, which can be fabricated via mechanical exfoliation of bulk SnP<sub>2</sub>S<sub>6</sub> crystals. Switchable polarization is observed in thin SnP<sub>2</sub>S<sub>6</sub> of ∼7 nm. Importantly, a van der Waals ferroelectric field-effect transistor (Fe-FET) with ferroelectric SnP<sub>2</sub>S<sub>6</sub> as top-gate insulator and p-type WTe<sub>0.6</sub>Se<sub>1.4</sub> as the channel was designed and fabricated successfully, which exhibits a clear clockwise hysteresis loop in transfer characteristics, demonstrating ferroelectric properties of SnP<sub>2</sub>S<sub>6</sub> atomic layers. In addition, a multilayer graphene/SnP<sub>2</sub>S<sub>6</sub>/multilayer graphene van der Waals vertical heterostructure phototransistor was also fabricated successfully, exhibiting improved optoelectronic performances with a responsivity (<i>R</i>) of 2.9 A/W and a detectivity (<i>D</i>) of 1.4 × 10<sup>12</sup> Jones. Our results show that SnP<sub>2</sub>S<sub>6</sub> is a promising 2D ferroelectric material for ferroelectric-integrated low-power 2D devices.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 4","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139103585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

High-resolution recognition of FOAM modes via an improved EfficientNet V2 based convolutional neural network 通过基于 EfficientNet V2 的改进型卷积神经网络高分辨率识别 FOAM 模式

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-03 DOI: 10.1007/s11467-023-1373-4

Youzhi Shi, Zuhai Ma, Hongyu Chen, Yougang Ke, Yu Chen, Xinxing Zhou

{"title":"High-resolution recognition of FOAM modes via an improved EfficientNet V2 based convolutional neural network","authors":"Youzhi Shi, Zuhai Ma, Hongyu Chen, Yougang Ke, Yu Chen, Xinxing Zhou","doi":"10.1007/s11467-023-1373-4","DOIUrl":"10.1007/s11467-023-1373-4","url":null,"abstract":"<div><p>Vortex beam with fractional orbital angular momentum (FOAM) is the excellent candidate for improving the capacity of free-space optical (FSO) communication system due to its infinite modes. Therefore, the recognition of FOAM modes with higher resolution is always of great concern. In this work, through an improved EfficientNetV2 based convolutional neural network (CNN), we experimentally achieve the implementation of the recognition of FOAM modes with a resolution as high as 0.001. To the best of our knowledge, it is the first time this high resolution has been achieved. Under the strong atmospheric turbulence (AT) <span>((C_n^2 = {10^{ - 15}},{{rm{m}}^{ - 2/3}}))</span>, the recognition accuracy of FOAM modes at 0.1 and 0.01 resolution with our model is up to 99.12% and 92.24% for a long transmission distance of 2000 m. Even for the resolution at 0.001, the recognition accuracy can still remain at 78.77%. This work provides an effective method for the recognition of FOAM modes, which may largely improve the channel capacity of the free-space optical communication.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139103739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Cavity-enhanced metrology in an atomic spin-1 Bose–Einstein condensate 原子自旋-1 玻色-爱因斯坦凝聚体中的空腔增强计量学

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2024-01-02 DOI: 10.1007/s11467-023-1372-5

Renfei Zheng, Jieli Qin, Bing Chen, Xingdong Zhao, Lu Zhou

引用次数: 0

Optimization for epitaxial fabrication of infinite-layer nickelate superconductors 优化无限层镍酸盐超导体的外延制造

IF 7.5 2区物理与天体物理

Frontiers of Physics Pub Date : 2023-12-28 DOI: 10.1007/s11467-023-1368-1

Minghui Xu, Yan Zhao, Xiang Ding, Huaqian Leng, Shu Zhang, Jie Gong, Haiyan Xiao, Xiaotao Zu, Huiqian Luo, Ke-Jin Zhou, Bing Huang, Liang Qiao

{"title":"Optimization for epitaxial fabrication of infinite-layer nickelate superconductors","authors":"Minghui Xu, Yan Zhao, Xiang Ding, Huaqian Leng, Shu Zhang, Jie Gong, Haiyan Xiao, Xiaotao Zu, Huiqian Luo, Ke-Jin Zhou, Bing Huang, Liang Qiao","doi":"10.1007/s11467-023-1368-1","DOIUrl":"10.1007/s11467-023-1368-1","url":null,"abstract":"<div><p>The discovery of nickelates superconductor creates exciting opportunities to unconventional superconductivity. However, its synthesis is challenging and only a few groups worldwide can obtain samples with zero-resistance. This problem becomes the major barrier for this field. From plume dynamics perspective, we found the synthesis of superconducting nickelates is a complex process and the challenge is twofold, i.e., how to stabilize an ideal infinite-layer structure Nd<sub>0.8</sub>Sr<sub>0.2</sub>NiO<sub>2</sub>, and then how to make Nd<sub>0.8</sub>Sr<sub>0.2</sub>NiO<sub>2</sub> superconducting? The competition between perovskite Nd<sub>0.8</sub>Sr<sub>0.2</sub>NiO<sub>3</sub> and Ruddlesden–Popper defect phase is crucial for obtaining infinite-layer structure. Due to inequivalent angular distributions of condensate during laser ablation, the laser energy density is critical to obtain phase-pure Nd<sub>0.8</sub>Sr<sub>0.2</sub>NiO<sub>3</sub>. However, for obtaining superconductivity, both laser energy density and substrate temperature are very important. We also demonstrate the superconducting Nd<sub>0.8</sub>Sr<sub>0.2</sub>NiO<sub>2</sub> epitaxial film is very stable in ambient conditions up to 512 days. Our results provide important insights for fabrication of superconducting infinite-layer nickelates towards future device applications.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139054445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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