Science China Physics, Mechanics & Astronomy最新文献

{"title":"Forecast of cosmological constraints with superluminous supernovae from the Chinese Space Station Telescope","authors":"Xuan-Dong Jia,&nbsp;Jian-Ping Hu,&nbsp;Fa-Yin Wang,&nbsp;Zi-Gao Dai","doi":"10.1007/s11433-024-2425-8","DOIUrl":"10.1007/s11433-024-2425-8","url":null,"abstract":"<div><p>Superluminous supernovae (SLSNe) are a class of intense celestial events that can be standardized for measuring cosmological parameters, bridging the gap between type Ia supernovae and the cosmic microwave background. In this work, we discuss the cosmological applications of SLSNe from the Chinese Space Station Telescope (CSST). Our estimation suggests that SLSNe rate is biased tracing the cosmic star formation rate, exhibiting a factor of (1 + <i>z</i>)^1.2. We futher predict that CSST is poised to observe ∼ 360 SLSNe in the 10 square degrees ultra-deep field survey within a span of 2.5 years. A stringent constraint on cosmological parameters can be derived from their peak-color relationship. CSST is anticipated to uncover a substantial number of SLSNe, contributing to a deeper understanding of their central engines and shedding light on the nature of dark energy at high redshifts.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Encoding innumerable charge density waves of FeGe into polymorphs of LiFe6Ge6","authors":"Yilin Wang","doi":"10.1007/s11433-024-2423-2","DOIUrl":"10.1007/s11433-024-2423-2","url":null,"abstract":"<div><p>Kagome metals exhibit rich quantum states by the intertwining of lattice, charge, orbital and spin degrees of freedom. Recently, a novel charge density wave (CDW) ground state was discovered in kagome magnet FeGe and was revealed to be driven by lowering magnetic energy via large Ge1-dimerization. Here, based on DFT calculations, we show that such mechanism will yield infinitely many metastable CDWs in FeGe due to different ways to arrange the Ge1-dimerization in enlarged superstructures. Intriguingly, utilizing these metastable CDWs, innumerable polymorphs of kagome magnet LiFe₆Ge₆ can be stabilized by filling Li atoms in the voids right above/below the dimerized Ge1-sites in the CDW superstructures. Such polymorphs are very stable due to the presence of magnetic-energy-saving mechanism, in sharp contrast to the non-magnetic “166” kagome compounds. In this way, a one-to-one mapping of the metastable CDWs of FeGe to stable polymorphs of LiFe₆Ge₆ is established. On one hand, the fingerprints of these metastable CDWs, i.e., the induced in-plane atomic distortions and band gaps, are encoded into the corresponding stable polymorphs of LiFe₆Ge₆, such that further study of their properties becomes possible. On the other hand, such innumerable polymorphs of LiFe₆Ge₆ offer great degrees of freedom to explore the rich physics of magnetic kagome metals. We thus reveal a novel connection between the unusually abundant CDWs and structural polymorphism in magnetic kagome materials, and establish a new route to obtain structural polymorphism on top of CDW states.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141609826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Spin-orbit interaction induced Casimir-Lifshitz torque between two-dimensional electron gases","authors":"Jia-Nan Rong,&nbsp;Liang Chen,&nbsp;Kai Chang","doi":"10.1007/s11433-024-2399-7","DOIUrl":"10.1007/s11433-024-2399-7","url":null,"abstract":"<div><p>We investigate theoretically the Casimir interaction between two parallel two-dimensional electron gases (2DEGs) with Rashba and Dresselhaus spin-orbit interactions (SOIs), based on the quantum field theory. We derive an analytical expression for the polarization tensor and obtain the solution to the motion equation of the electromagnetic (EM) field. We calculate the Casimir-Lifshitz torque (CLT) between two parallel 2DEGs with Rashba and Dresselhaus SOIs, which can be tuned by changing the relative strength between two SOIs. The anisotropic Casimir energy between 2DEGs caused by the interplay between the SOIs of 2DEGs offers a new origin of CLT and a new type of optoelectronic device.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Unusual photocarrier and coherent phonon dynamics behaviors of layered PdSe2 unveiled by ultrafast spectroscopy of the edge surface","authors":"Tiantian Yun,&nbsp;Changfu Huo,&nbsp;Jinluo Cheng,&nbsp;Zhi-Bo Liu,&nbsp;Xiao-Qing Yan","doi":"10.1007/s11433-024-2401-1","DOIUrl":"10.1007/s11433-024-2401-1","url":null,"abstract":"<div><p>Layered materials exhibit different electronic and phonon properties along in-plane and out-of-plane directions; existing studies focus on their in-plane behaviors, and the influence of such anisotropies on the dynamics of photocarriers and phonons is unknown. Here, we fabricate layered PdSe₂ crystals with flat edge surfaces and compare the time-resolved ultrafast spectroscopies on their basal and edge surfaces. Pronounced differences in the transient reflection spectroscopies reveal the inconsistent photocarrier and phonon dynamics behaviors on the two surfaces: the slow hot carrier relaxation process is accelerated and the thermoelasticity-induced longitudinal coherent acoustic phonon oscillation completely vanishes on the edge surface, as compared with the basal surface. Theoretical analysis reveals that the inconsistent hot carrier dynamics originate from the anisotropic properties of low-energy phonons in PdSe₂, and the absence of phonon oscillation on the edge surface results from the wavevector-limited sensitivity of acoustic <i>B</i>_1<i>u</i> mode. Moreover, polarization-dependent spectroscopies indicate the diverse optical anisotropies beyond the in-plane of PdSe₂. This work provides a new method to explore unique physical properties and modulate the optical anisotropy of layered materials.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141609942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Exploring charge and spin fluctuations in infinite-layer cuprate SrCuO2 from a phonon perspective","authors":"Xin Du,&nbsp;Pei-Han Sun,&nbsp;Ben-Chao Gong,&nbsp;Jian-Feng Zhang,&nbsp;Zhong-Yi Lu,&nbsp;Kai Liu","doi":"10.1007/s11433-024-2388-y","DOIUrl":"10.1007/s11433-024-2388-y","url":null,"abstract":"<div><p>The infinite-layer cuprate <i>A</i>CuO₂ (<i>A</i> = Ca, Sr, Ba) possesses the simplest crystal structure among numerous cuprate superconductors and can serve as a prototypical system to explore the unconventional superconductivity. Based on the first-principles electronic structure calculations, we have studied the electronic and magnetic properties of the infinite-layer cuprate SrCuO₂ from a phonon perspective. We find that interesting fluctuations of charges, electrical dipoles, and local magnetic moments can be induced by the atomic displacements of phonon modes in SrCuO₂ upon the hole doping. Among all optical phonon modes of SrCuO₂ in the antiferromagnetic Néel state, only the <i>A</i>_1<i>g</i> mode that involves the full-breathing O vibrations along the Cu-O bonds can cause significant fluctuations of local magnetic moments on O atoms and dramatic charge redistributions between Cu and O atoms. Notably, due to the atomic displacements of the <i>A</i>_1<i>g</i> mode, both the charge fluctuations on Cu and the electrical dipoles on O show a dome-like evolution with increasing hole doping, quite similar to the experimentally observed behavior of the superconducting <i>T</i>_<i>c</i>; in comparison, the fluctuations of local magnetic moments on O display a monotonic enhancement along with the hole doping. Further analyses indicate that around the optimal doping, there exists a large softening in the frequency of the <i>A</i>_1<i>g</i> phonon mode and a van Hove singularity in the electronic structure close to the Fermi level, suggesting potential electron-phonon coupling. Our work reveals the important role of the full-breathing O phonon mode playing in the infinite-layer SrCuO₂, which may provide new insights in understanding the cuprate superconductivity.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141609943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Harpoon-shaped topological photonic crystal for on-chip beam splitter","authors":"Zhiwei Guan,&nbsp;Ruixue Dou,&nbsp;Chuangxin Xie,&nbsp;Tianyimei Zuo,&nbsp;Liyu Huang,&nbsp;Keyin Wen,&nbsp;Chaofeng Wang,&nbsp;Huapeng Ye,&nbsp;Junmin Liu,&nbsp;Ze Dong,&nbsp;Dianyuan Fan,&nbsp;Shuqing Chen","doi":"10.1007/s11433-024-2421-3","DOIUrl":"10.1007/s11433-024-2421-3","url":null,"abstract":"<div><p>The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network nodes. However, the pursuit of micron-scale beam splitting with large corners and reducing the device footprint to boost connection flexibility often results in phase mismatches. These mismatches, which stem from radiation modes and backward scattering, pose significant obstacles in creating highly integrated and interference-resistant connections. To address this, we introduce a solution based on the topological valley-contrasting state generated by photonic crystals with opposing valley Chern numbers, manifested in a harpoon-shaped structure designed to steer the splitting channels. This approach enables adiabatic mode field evolution over large corners, capitalizing on the robust phase modulation capabilities and topological protection provided by the subwavelength-scale valley-contrasting state. Our demonstration reveals that beam splitters with large corners of 60°, 90°, and 120° exhibit insertion loss fluctuations below 2.7 dB while maintaining a minimal footprint of 8.8 µm × 8.8 µm. As a practical demonstration, these devices facilitate three-channel signal connections, successfully transmitting quadrature phase shift keying signals at 3.66 Tbit/s with bit error rates below the forward error correction threshold, demonstrating performance comparable to that in defects scenarios. By harnessing the unidirectional excitation feature, we anticipate significant enhancements in the capabilities of signal distribution and connection networks through a daisy chain configuration.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"The ALMaQUEST Survey XV: The dependence of the molecular-to-atomic gas ratios on resolved optical diagnostics","authors":"Niankun Yu,&nbsp;Zheng Zheng,&nbsp;Chao-Wei Tsai,&nbsp;Pei Zuo,&nbsp;Sara L. Ellison,&nbsp;David V. Stark,&nbsp;Di Li,&nbsp;Jingwen Wu,&nbsp;Karen L. Masters,&nbsp;Ting Xiao,&nbsp;Yinghui Zheng,&nbsp;Zongnan Li,&nbsp;Kai Zhang,&nbsp;Hongying Chen,&nbsp;Shu Liu,&nbsp;Sihan Jiao,&nbsp;Fanyi Meng","doi":"10.1007/s11433-023-2387-2","DOIUrl":"10.1007/s11433-023-2387-2","url":null,"abstract":"<div><p>The atomic-to-molecular gas conversion is a critical step in the baryon cycle of galaxies, which sets the initial conditions for subsequent star formation and influences the multi-phase interstellar medium. We compiled a sample of 94 nearby galaxies with observations of multi-phase gas contents by utilizing public H<span>i</span>, CO, and optical IFU data from the MaNGA survey together with new FAST H<span>i</span> observations. In agreement with previous results, our sample shows that the global molecular-to-atomic gas ratio (<span>(R_{text{mol}}equivtext{log} M_{rm{H}_{2}}/M_{rm{H}_{1}})</span>) is correlated with the global stellar mass surface density <i>μ</i>_* with a Kendall’s <i>τ</i> coefficient of 0.25 and <i>p</i> &lt; 10⁻³, less tightly but still correlated with stellar mass and NUV–r color, and not related to the specific star formation rate (sSFR). The cold gas distribution and kinematics inferred from the H<span>i</span> and CO global profile asymmetry and shape do not significantly rely on <i>R</i>_mol. Thanks to the availability of kpc-scale observations of MaNGA, we decompose galaxies into H<span>ii</span>, composite, and AGN-dominated regions by using the BPT diagrams. With increasing <i>R</i>_mol, the fraction of H<span>ii</span> regions within 1.5 effective radius decreases slightly; the density distribution in the spatially resolved BPT diagram also changes significantly, suggesting changes in metallicity and ionization states. Galaxies with high <i>R</i>_mol tend to have high oxygen abundance, both at one effective radius with a Kendall’s <i>τ</i> coefficient of 0.37 (<i>p</i> &lt; 10⁻³) and their central regions. Among all parameters investigated here, the oxygen abundance at one effective radius has the strongest relation with global <i>R</i>_mol. The dependence of gas conversion on gas distribution and galaxy ionization states is weak. In contrast, the observed positive relation between oxygen abundance (<i>μ</i>_*) and <i>R</i>_mol indicates that the gas conversion is efficient in regions of high metallicity (density).</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Pressure-triggered stacking dependence of interlayer coupling in bilayer WS2","authors":"Zejuan Zhang,&nbsp;Chenyin Jiao,&nbsp;Shenghai Pei,&nbsp;Xilong Zhou,&nbsp;Jiaze Qin,&nbsp;Wanli Zhang,&nbsp;Yu Zhou,&nbsp;Zenghui Wang,&nbsp;Juan Xia","doi":"10.1007/s11433-024-2376-9","DOIUrl":"10.1007/s11433-024-2376-9","url":null,"abstract":"<div><p>Tungsten disulfide (WS₂) has been reported to show negligible stacking dependence under ambient conditions, impeding its further explorations on physical properties and potential applications. Here, we realize efficient modulation of interlayer coupling in bilayer WS₂ with 3R and 2H stackings by high pressure, and find that the pressure-triggered interlayer coupling and pressure-induced resonant-to-nonresonant transition exhibit prominent stacking dependence, which are experimentally observed for the first time in WS₂. Our work may unleash the stacking degree of freedom in designing WS₂ devices with tailored properties correlated to interlayer coupling.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Isolation performances and optimization of triple quasi-zero stiffness isolators","authors":"Yuntian Zhang,&nbsp;Guangnan Zhu,&nbsp;Qingjie Cao","doi":"10.1007/s11433-023-2371-0","DOIUrl":"10.1007/s11433-023-2371-0","url":null,"abstract":"<div><p>In this paper, triple quasi-zero stiffness (QZS) passive vibration isolators whose restoring force curve has a three-stage softening effect are proposed. Multi-coupled SD oscillators with three independent geometrical parameters are used as negative stiffness mechanisms to achieve QZS characteristics at the origin and symmetrical positions on both sides of the origin. Isolation performances of different triple QZS isolators are analyzed to show influences of the selection of QZS regions away from the origin on the range of isolation regions. Pareto optimizations of system parameters are carried out to get a larger range of small restoring force regions and small stiffness regions. Isolation performances of two triple QZS isolators are discussed to show the influence of different Pareto optimization solutions through the comparisons with single and double QZS isolators. Results showed that triple QZS isolators have both the advantages of single and double QZS isolators which results in better isolation performances under both small and large excitation amplitudes. An improvement in isolation performances for triple QZS isolators is found with the decrease in average stiffness due to the appearance of two symmetrical QZS regions away from the origin. Larger displacements of QZS regions away from the origin result in better isolation performances when excitation amplitude is large, and triple QZS characteristics are similar to double QZS isolators at this time. Smaller restoring forces of QZS regions away from the origin lead to better isolation performances when excitation amplitude is small, and triple QZS characteristics are similar to single QZS isolators at this moment. Compared with the decrease in average stiffness, the improvement of isolation performances shows a hysteresis phenomenon due to the difference between static and dynamic characteristics.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}

{"title":"Quasi-2D weak lensing cosmological constraints using the PDF-SYM method","authors":"Zhenjie Liu,&nbsp;Jun Zhang,&nbsp;Hekun Li,&nbsp;Zhi Shen,&nbsp;Cong Liu","doi":"10.1007/s11433-024-2379-0","DOIUrl":"10.1007/s11433-024-2379-0","url":null,"abstract":"<div><p>Cosmic shear statistics, such as the two-point correlation function (2PCF), can be evaluated with the PDF-SYM method instead of the traditional weighted-sum approach. It makes use of the full PDF information of the shear estimators, and does not require weightings on the shear estimators, which can in principle introduce additional systematic biases. This work presents our constraints on <i>S</i>₈ and Ω_m from the shear-shear correlations using the PDF-SYM method. The data we use is from the <i>z</i>-band images of the Dark Energy Camera Legacy Survey (DECaLS), which covers about 10000 deg² with more than 100 million galaxies. The shear catalog is produced by the Fourier_Quad method, and well tested on the real data itself with the field-distortion effect. Our main approach is called quasi-2D as we do use the photo-<i>z</i> information of each individual galaxy, but without dividing the galaxies into redshift bins. We mainly use galaxy pairs within the redshift interval between 0.2 and 1.3, and the angular range from 4.7 to 180 arcmin. Our analysis yields <i>S</i>₈ = 0.762 ± 0.026 and Ω_m = 0.234 ± 0.075, with the baryon effects and the intrinsic alignments included. The results are robust against redshift uncertainties. We check the consistency of our results by deriving the cosmological constraints from auto-correlations of <i>γ</i>₁ and <i>γ</i>₂ separately, and find that they are consistent with each other, but the constraints from the <i>γ</i>₁ component are much weaker than that from <i>γ</i>₂. It implies a much worse data quality of <i>γ</i>₁, which is likely due to additional shear uncertainties caused by CCD electronics (according to the survey strategy of DECaLS). We also perform a pure 2D analysis, which gives <i>S</i>₈ = 0.81<span>\u0000 ^+0.03_−0.04\u0000 \u0000 </span> and Ω_m = 0.25<span>\u0000 ^+0.06_−0.05\u0000 \u0000 </span>. Our findings demonstrate the potential of the PDF-SYM method for precision cosmology.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}