Science China Physics, Mechanics & Astronomy最新文献

{"title":"Imaging momentum-space Cooper pair formation and its competition with the charge density wave gap in a kagome superconductor","authors":"Yiming Sun,&nbsp;Yubing Tu,&nbsp;Yang Luo,&nbsp;Shuikang Yu,&nbsp;Hongyu Li,&nbsp;Yunmei Zhang,&nbsp;Ping Wu,&nbsp;Zhuying Wang,&nbsp;Fan Zhang,&nbsp;Wanru Ma,&nbsp;Zuowei Liang,&nbsp;Jianjun Ying,&nbsp;Tao Wu,&nbsp;Ziji Xiang,&nbsp;Junfeng He,&nbsp;Lei Shan,&nbsp;Zhenyu Wang,&nbsp;Xianhui Chen","doi":"10.1007/s11433-023-2360-y","DOIUrl":"10.1007/s11433-023-2360-y","url":null,"abstract":"<div><p>The superconducting ground state of kagome metals <i>A</i>V₃Sb₅ (where <i>A</i> stands for K, Rb, or Cs) emerges from an exotic charge density wave (CDW) state that potentially breaks both rotational and time reversal symmetries. However, the specifics of the Cooper pairing mechanism, and the nature of the interplay between these two states remain elusive, largely due to the lack of momentum-space (<i>k</i>-space) superconducting energy gap structure. By implementing Bogoliubov quasiparticle interference (BQPI) imaging, we obtain <i>k</i>-space information on the multiband superconducting gap structure Δ<span>\u0000 ^<i>i</i>_SC\u0000 \u0000 </span>(<i>k</i>) in pristine CsV₃Sb₅. We show that the estimated energy gap on the vanadium <span>({d_{x{y mathord{left/ {vphantom {y {{x^{rm{2}}} - {y^{rm{2}}}}}} right.} {{x^{rm{2}}} - {y^{rm{2}}}}}}})</span> orbital is anisotropic but nodeless, with a minimal value located near the M point. Interestingly, a comparison of Δ<span>\u0000 ⁱ_SC\u0000 \u0000 </span>(<i>k</i>) with the CDW gap Δ<span>\u0000 ^<i>i</i>_CDW\u0000 \u0000 </span>(<i>k</i>) obtained by angle-resolved photoemission spectroscopy (ARPES) reveals direct <i>k</i>-space competition between these two order parameters, i.e., the opening of a large (small) CDW gap at a given momentum corresponds to a small (large) superconducting gap. When the long-range CDW order is suppressed by replacing vanadium with titanium, we find a nearly isotropic energy gap on both the V and Sb bands. This information will be critical for identifying the microscopic pairing mechanism and its interplay with intertwined electronic orders in this kagome superconductor family.</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":"141502619","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":"Near real-time gravitational wave data analysis of the massive black hole binary with TianQin","authors":"Hong-Yu Chen,&nbsp;Xiang-Yu Lyu,&nbsp;En-Kun Li,&nbsp;Yi-Ming Hu","doi":"10.1007/s11433-023-2377-7","DOIUrl":"10.1007/s11433-023-2377-7","url":null,"abstract":"<div><p>Space-borne gravitational wave (GW) detectors can detect the merger of massive black holes. The early warning and localization of GW events before merging can be used to inform electromagnetic telescopes and conduct multimessenger observations. However, this requires real-time data transmission and analysis capabilities. The geocentric orbit of the space-borne GW detector TianQin makes it possible to conduct real-time data transmission. In this study, we develop a search and localization pipeline for massive black hole binaries (MBHBs) with TianQin under both regular and real-time data transmission modes. We demonstrate that, with real-time data transmission, MBHBs can be accurately localized on the fly. With the approaching merger, each analysis can be finished in only 40 min. For an MBHB system at a distance of 1 Gpc, if we receive data every hour, then we can pinpoint its location to within less than 1 deg² on the final day before the merger.</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":"141502620","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":"Refined acoustic holography via nonlocal metasurfaces","authors":"Shuhuan Xie,&nbsp;Hongyu Ma,&nbsp;Junmei Cao,&nbsp;Fangshuo Mo,&nbsp;Qian Cheng,&nbsp;Yong Li,&nbsp;Tong Hao","doi":"10.1007/s11433-023-2359-6","DOIUrl":"10.1007/s11433-023-2359-6","url":null,"abstract":"<div><p>Holography can provide the desired wavefront phase and/or amplitude for imaging, particle manipulation, bacteria trapping, and cell patterning in optics and acoustics. However, previous work on acoustic holography is mostly based on local design optimization, either using active control of the sound source or relying on the structural design to provide the desired wavefront. Achieving precise control over the acoustic field remains a significant challenge. Here, we realize refined single-plane symmetric binary amplitude, asymmetric intensity gradient amplitude, and bi-objective hologram through the non-local holographic imaging theory that considers the acoustic coupling of structural units in detail. By taking into account the self-radiation and mutual radiation between many small units on a plate of well-designed thickness, as well as the transmission through the plate’s apertures, we can effectively regulate the sound field behind the plate. We demonstrate the effectiveness of our approach through numerical simulations and experiments, showcasing a circle, a black hole, and a bi-objective with a circle and a square hologram. Notably, the acoustic black hole hologram precisely reconstructs the intensity gradient distribution at two bright spots. This non-local holographic imaging theory is valuable for the fine-intensity regulation of the sound field and is expected to be applied in ultrasound diagnosis and treatment, medical imaging, and other fields.</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":"141528789","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":"A polarized 3He system based on metastability-exchange optical pumping","authors":"Yuting Wang,&nbsp;Liangyong Wu,&nbsp;Kaiyuan Zhang,&nbsp;Mei Peng,&nbsp;Siyu Chen,&nbsp;Haiyang Yan","doi":"10.1007/s11433-023-2355-7","DOIUrl":"10.1007/s11433-023-2355-7","url":null,"abstract":"<div><p>Hyperpolarized ³He nuclei have emerged as a significantly important approach in quantum precision measurement techniques, with extensive applications in fundamental physics, magnetometry, metrology, and beyond. In this study, we report on the design and implementation of a ³He polarization system at the China Mianyang Research Reactor (CMRR), utilizing the metastability-exchange optical pumping (MEOP) method. We employed a Merritt coil system consisting of four square coils to furnish a uniform holding field. We deployed a 2 W fiber laser to pump the metastable ³He atoms and conducted free induction decay (FID) detection of the polarized ³He nuclei using both pickup coil and optical methods. For the optical method, we used a 50 mW linearly polarized distributed Bragg reflector (DBR) laser as the probe. We applied transverse light absorption polarimetry to measure the absolute nuclear polarization of the ground-state ³He. We have developed cell fabrication capabilities at the CMRR, and cells at various pressures ranging from 100 to 1000 Pa have been fabricated and evaluated. For a typical borosilicate cell with 100 Pa pressure, the absolute polarization is measured as <i>P</i>_<i>n</i> ≈ 70%, and the transverse relaxation time is estimated as <i>T</i>₂ ≈ 0.5 s. Moreover, we constructed a few aluminosilicate cells, each carefully filled with pure ³He at a pressure of 100 Pa. Subsequently, we conducted a comprehensive evaluation of their performance in the context of MEOP.</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":"141502618","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":"Even-odd layer-dependent multiferroic in freestanding rare-earth orthorhombic perovskite","authors":"Shaowen Xu,&nbsp;Fanhao Jia,&nbsp;Ning Dai","doi":"10.1007/s11433-024-2372-8","DOIUrl":"10.1007/s11433-024-2372-8","url":null,"abstract":"<div><p>Freestanding oxide perovskites possess strong interlayer coupling between adjacent atomic layers, thus exerting a determinative effect on the magnetism and ferroelectricity of these atomic-scale materials. Here, we propose an effective strategy to manipulate magnetism and ferroelectricity in freestanding rare-earth orthorhombic perovskite via modulation of layer thickness. By performing first-principles calculations, an even-odd oscillation is demonstrated in few-layer GdAlO₃ perovskite (GAP). Specifically, odd-layer systems with charged atomic layers are ferromagnetic polar metals, while even-layer systems are antiferromagnetic ferroelectric semiconductors. This thickness-dependent magnetic phase transition originates from carrier doping, as rationalized by the Stoner criterion. Furthermore, we demonstrate the promotion of in-plane ferroelectricity via the concurrent application of two distinct antiferrodistortive displacements, each driven by formation and breaking of bonds. Analogous multiferroic phases may emerge in other transition metal oxide perovskites supporting multiple valence states, e.g., few-layer GdMO₃ (M = V, Cr, Mn, and Ni). This work puts forward a strategy for layer thickness engineering of magnetism and ferroelectricity in 2D oxide perovskite multiferroic materials.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502621","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":"Security of quantum key distribution with virtual mutually unbiased bases","authors":"Hong-Wei Li,&nbsp;Chen-Peng Hao,&nbsp;Zhi-Jiang Chen,&nbsp;Li Gong,&nbsp;Yi-Fei Lu,&nbsp;Yang Wang,&nbsp;Jia-Ji Li,&nbsp;Chun-Mei Zhang,&nbsp;Rong Wang,&nbsp;Zhen-Qiang Yin,&nbsp;Qing-Yu Cai","doi":"10.1007/s11433-024-2378-1","DOIUrl":"10.1007/s11433-024-2378-1","url":null,"abstract":"<div><p>In a perfect quantum key distribution (QKD) protocol, quantum states should be prepared and measured with mutually unbiased bases (MUBs). However, in a practical QKD system, quantum states are generally prepared and measured with imperfect MUBs using imperfect devices, possibly reducing the secret key rate and transmission distance. To analyze the security of a QKD system with imperfect MUBs, we propose virtual MUBs to characterize the quantum channel against collective attack, and analyze the corresponding secret key rate under imperfect state preparation and measurement conditions. More generally, we apply the advantage distillation method for analyzing the security of QKD with imperfect MUBs, where the error tolerance and transmission distance can be sharply improved. Our analysis method can be applied to benchmark and standardize a practical QKD system, elucidating the security analysis of different QKD protocols with imperfect devices.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502622","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":"Inversely engineered metasurfaces for independent manipulation of transmitted and reflected light fields","authors":"Yongjian Liu,&nbsp;Yu Luo,&nbsp;Fei Zhang,&nbsp;Mingbo Pu,&nbsp;Hanlin Bao,&nbsp;Mingfeng Xu,&nbsp;Yinghui Guo,&nbsp;Lanting Li,&nbsp;Xiong Li,&nbsp;Xiaoliang Ma,&nbsp;Xiangang Luo","doi":"10.1007/s11433-024-2375-8","DOIUrl":"10.1007/s11433-024-2375-8","url":null,"abstract":"<div><p>Independent manipulation of transmitted and reflected light fields is a key technology for the realization of multifunctional optical applications, which can be implemented based on multilayered plasmonic or supercell subwavelength structures. However, the former is not suitable for the optical bands, while the latter is insufficient in generating large phase gradients. Here, an adjoint-optimization-based inverse design methodology is proposed, which utilizes the polarization-selective local interference between individual meta-atoms and enables monolayer dielectric metasurfaces to decouple the wavefront of transmitted and reflected optical fields. Moreover, this methodology serves to mitigate the aperiodic electromagnetic crosstalk inherent between adjacent meta-atoms, consequently leading to a significant enhancement in the performance of meta-devices. We analyzed the physical mechanism of adjoint optimization and proposed the concept of phase factors, highlighting their importance in the rapid inverse design of meta-devices-an aspect often overlooked in previous research. To demonstrate the feasibility and robustness of our method, we optimize monolayer metasurfaces with different initial structures. These devices efficiently focus and deflect <i>x</i>-linearly and <i>y</i>-linearly polarized incident light in transmission and reflection spaces, respectively. Overall, this methodology holds immense potential for designing multifunctional, high-performing metasurfaces that meet multiple constraints, opening up broad prospects for applications.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11433-024-2375-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implementation of integrated nonlocal sensing for object shape and rotational speed","authors":"Zhenyu Guo,&nbsp;Yunlong Wang,&nbsp;Zehong Chang,&nbsp;Jiawei Wang,&nbsp;Junliang Jia,&nbsp;Pei Zhang","doi":"10.1007/s11433-023-2364-0","DOIUrl":"10.1007/s11433-023-2364-0","url":null,"abstract":"<div><p>The expeditious acquisition of information pertaining to objects through the utilization of quantum technology has been a perennial issue of concern. So far, the efficient utilization of information from dynamic objects with limited resources remains a significant challenge. Here, we realize a nonlocal integrated sensing of the object’s amplitude and phase information by combining digital spiral imaging with the correlated orbital angular momentum states. The amplitude information is utilized for object identification, while the phase information enables us to determine the rotational speed. We demonstrate the nonlocal identification of a rotating object’s shape, irrespective of its rotational symmetry, and introduce the concept of the correlated rotational Doppler effect, establishing a fundamental connection between this effect and the classical rotational Doppler effect, i.e., that both rely on extracting crucial information from the spiral spectrum of objects. The present study highlights a promising pathway towards the realization of quantum remote sensing and imaging.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141352600","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":"Quantum integrated nonlocal sensing of dynamic object","authors":"Jiachen Liu,&nbsp;Qiwen Zhan","doi":"10.1007/s11433-024-2368-2","DOIUrl":"10.1007/s11433-024-2368-2","url":null,"abstract":"","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141351133","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":"New black-to-white hole solutions with improved geometry and energy conditions","authors":"Zhongwen Feng,&nbsp;Yi Ling,&nbsp;Xiaoning Wu,&nbsp;Qingquan Jiang","doi":"10.1007/s11433-023-2373-0","DOIUrl":"10.1007/s11433-023-2373-0","url":null,"abstract":"<div><p>We construct new black-to-white hole solutions which connect the geometry of spacetime at some gluing surface inside the horizon. The continuity of the metric can be guaranteed up to the arbitrary order which is controlled by the power factor n. This sort of black-to-white holes is characterized by the sub-Planckian scalar curvature, independent of the mass of black-to-white holes. More importantly, we show that the energy condition is only violated within a small region near the gluing surface. The geodesics of particles within the region from black hole to white hole is also analyzed. It turns out that the matter falling into the black hole may pass through the center without singularity and come out from the white hole. This scenario provides novel ideas for understanding the information loss paradox in traditional black hole physics.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502616","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}