Reports on progress in physics. Physical Society (Great Britain)最新文献

{"title":"The rigid unit mode model: review of ideas and applications.","authors":"Lei Tan, Volker Heine, Gong Li, Martin T Dove","doi":"10.1088/1361-6633/acc7b7","DOIUrl":"10.1088/1361-6633/acc7b7","url":null,"abstract":"<p><p>We review a set of ideas concerning the flexibility of network materials, broadly defined as structures in which atoms form small polyhedral units that are connected at corners. One clear example is represented by the family of silica polymorphs, with structures composed of corner-linked SiO₄tetrahedra. The rigid unit mode (RUM) is defined as any normal mode in which the structural polyhedra can translate and/or rotate without distortion, and since forces associated with changing the size and shape of the polyhedra are much stronger than those associated with rotations of two polyhedra around a shared vertex, the RUMs might be expected to have low frequencies compared to all other phonon modes. In this paper we discuss the flexibility of network structures, and how RUMs can arise in such structures, both in principle and in a number of specific examples of real systems. We also discuss applications of the RUM model, particularly for our understanding of phenomena such as displacive phase transitions and negative thermal expansion in network materials.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9547110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interatomic and intermolecular decay processes in quantum fluid clusters.","authors":"A C LaForge, L Ben Ltaief, S R Krishnan, N Sisourat, M Mudrich","doi":"10.1088/1361-6633/ad8fbb","DOIUrl":"10.1088/1361-6633/ad8fbb","url":null,"abstract":"<p><p>In this comprehensive review, we explore interatomic and intermolecular correlated electronic decay phenomena observed in superfluid helium nanodroplets subjected to extreme ultraviolet radiation. Helium nanodroplets, known for their distinctive electronic and quantum fluid properties, provide an ideal environment for examining a variety of non-local electronic decay processes involving the transfer of energy, charge, or both between neighboring sites and resulting in ionization and the emission of low-kinetic energy electrons. Key processes include interatomic or intermolecular Coulombic decay and its variants, such as electron transfer-mediated decay. Insights gained from studying these light-matter interactions in helium nanodroplets enhance our understanding of the effects of ionizing radiation on other condensed-phase systems, including biological matter. We also emphasize the advanced experimental and computational techniques that make it possible to resolve electronic decay processes with high spectral and temporal precision. Utilizing ultrashort pulses from free-electron lasers, the temporal evolution of these processes can be followed, significantly advancing our comprehension of the dynamics within quantum fluid clusters and non-local electronic interactions in nanoscale systems.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142607563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superscattering of light: fundamentals and applications.","authors":"Chan Wang, Xuhuinan Chen, Zheng Gong, Ruoxi Chen, Hao Hu, Huaping Wang, Yi Yang, Low Tony, Baile Zhang, Hongsheng Chen, Xiao Lin","doi":"10.1088/1361-6633/ad8eda","DOIUrl":"10.1088/1361-6633/ad8eda","url":null,"abstract":"<p><p>Superscattering, theoretically predicted in 2010 and experimentally observed in 2019, is an exotic scattering phenomenon of light from subwavelength nanostructures. In principle, superscattering allows for an arbitrarily large total scattering cross section, due to the degenerate resonance of eigenmodes or channels. Consequently, the total scattering cross section of a superscatterer can be significantly enhanced, far exceeding the so-called single-channel limit. Superscattering offers a unique avenue for enhancing light-matter interactions and can enable numerous practical applications, ranging from sensing, light trapping, bioimaging, and communications to optoelectronics. This paper provides a comprehensive review of the recent progress and developments in the superscattering of light, with a specific focus on elucidating its theoretical origins, experimental observations, and manipulations. Moreover, we offer an outlook on future research directions in superscattering, including potential realizations of directional superscattering, scattering-free plasmonic superscattering, enhancement of free-electron radiation and the Purcell effect via superscatterers, inelastic superscattering, and superscattering of non-electromagnetic waves.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142584944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topological phase transitions via attosecond x-ray absorption spectroscopy.","authors":"Juan F P Mosquera, Giovanni Cistaro, Mikhail Malakhov, Emilio Pisanty, Alexandre Dauphin, Luis Plaja, Alexis Chacón, Maciej Lewenstein, Antonio Picón","doi":"10.1088/1361-6633/ad889f","DOIUrl":"10.1088/1361-6633/ad889f","url":null,"abstract":"<p><p>We present a numerical experiment that demonstrates the possibility to capture topological phase transitions via an x-ray absorption spectroscopy scheme. We consider a Chern insulator whose topological phase is tuned via a second-order hopping. We perform time-dynamics simulations of the out-of-equilibrium laser-driven electron motion that enables us to model a realistic attosecond spectroscopy scheme. In particular, we use an ultrafast scheme with a circularly polarized IR pump pulse and an attosecond x-ray probe pulse. A laser-induced dichroism-type spectrum shows a clear signature of the topological phase transition. We are able to connect these signatures with the Berry structure of the system. This work extend the applications of attosecond absorption spectroscopy to systems presenting a non-trivial topological phase.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142482694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum algorithms for scientific computing.","authors":"R Au-Yeung, B Camino, O Rathore, V Kendon","doi":"10.1088/1361-6633/ad85f0","DOIUrl":"10.1088/1361-6633/ad85f0","url":null,"abstract":"<p><p>Quantum computing promises to provide the next step up in computational power for diverse application areas. In this review, we examine the science behind the quantum hype, and the breakthroughs required to achieve true quantum advantage in real world applications. Areas that are likely to have the greatest impact on high performance computing (HPC) include simulation of quantum systems, optimization, and machine learning. We draw our examples from electronic structure calculations and computational fluid dynamics which account for a large fraction of current scientific and engineering use of HPC. Potential challenges include encoding and decoding classical data for quantum devices, and mismatched clock speeds between classical and quantum processors. Even a modest quantum enhancement to current classical techniques would have far-reaching impacts in areas such as weather forecasting, aerospace engineering, and the design of 'green' materials for sustainable development. This requires significant effort from the computational science, engineering and quantum computing communities working together.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142407311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observation of quantum entanglement in top quark pair production in proton-proton collisions ats=13 TeV.","authors":"The Cms Collaboration","doi":"10.1088/1361-6633/ad7e4d","DOIUrl":"10.1088/1361-6633/ad7e4d","url":null,"abstract":"<p><p>Entanglement is an intrinsic property of quantum mechanics and is predicted to be exhibited in the particles produced at the Large Hadron Collider. A measurement of the extent of entanglement in top quark-antiquark (tt¯) events produced in proton-proton collisions at a center-of-mass energy of 13 TeV is performed with the data recorded by the CMS experiment at the CERN LHC in 2016, and corresponding to an integrated luminosity of 36.3 fb^-1. The events are selected based on the presence of two leptons with opposite charges and high transverse momentum. An entanglement-sensitive observable<i>D</i>is derived from the top quark spin-dependent parts of thett¯production density matrix and measured in the region of thett¯production threshold. Values ofD<-1/3are evidence of entanglement and<i>D</i>is observed (expected) to be-0.480-0.029+0.026(-0.467-0.029+0.026) at the parton level. With an observed significance of 5.1 standard deviations with respect to the non-entangled hypothesis, this provides observation of quantum mechanical entanglement withintt¯pairs in this phase space. This measurement provides a new probe of quantum mechanics at the highest energies ever produced.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142309322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuously tunable single-photon level nonlinearity with Rydberg state wave-function engineering.","authors":"Biao Xu, Gen-Sheng Ye, Yue Chang, Tao Shi, Lin Li","doi":"10.1088/1361-6633/ad847e","DOIUrl":"10.1088/1361-6633/ad847e","url":null,"abstract":"<p><p>Extending optical nonlinearity into the extremely weak light regime is at the heart of quantum optics, since it enables the efficient generation of photonic entanglement and implementation of photonic quantum logic gate. Here, we demonstrate the capability for continuously tunable single-photon level nonlinearity, enabled by precise control of Rydberg interaction over two orders of magnitude, through the use of microwave-assisted wave-function engineering. To characterize this nonlinearity, light storage and retrieval protocol utilizing Rydberg electromagnetically induced transparency is employed, and the quantum statistics of the retrieved photons are analyzed. As a first application, we demonstrate our protocol can speed up the preparation of single photons in low-lying Rydberg states by a factor of up to∼40. Our work holds the potential to accelerate quantum operations and to improve the circuit depth and connectivity in Rydberg systems, representing a crucial step towards scalable quantum information processing with Rydberg atoms.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142395813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expressibility-induced Concentration of Quantum Neural Tangent Kernels.","authors":"Li-Wei Yu, Weikang Li, Qi Ye, Zhide Lu, Zizhao Han, Dong-Ling Deng","doi":"10.1088/1361-6633/ad82cf","DOIUrl":"https://doi.org/10.1088/1361-6633/ad82cf","url":null,"abstract":"<p><p>Quantum tangent kernel methods provide an efficient approach to analyzing the performance of quantum machine learning models in the infinite-width limit, which is of crucial importance in designing appropriate circuit architectures for certain learning tasks. Recently, they have been adapted to describe the convergence rate of training errors in quantum neural networks in an analytical manner. Here, we study the connections between the expressibility and value concentration of quantum tangent kernel models. In particular, for global loss functions, we rigorously prove that high expressibility of both the global and local quantum encodings can lead to exponential concentration of quantum tangent kernel values to zero. Whereas for local loss functions, such issue of exponential concentration persists owing to the high expressibility, but can be partially mitigated. We further carry out extensive numerical simulations to support our analytical theories. Our discoveries unveil a fundamental feature of quantum neural tangent kernels, indicating that the issue of their concentration cannot be bypassed merely by transitioning to a local encoding scheme while maintaining high expressibility. This offers valuable insights for the design of wide quantum variational circuit models in practical applications.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142367779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exact results of the one-dimensional repulsive Hubbard model.","authors":"Jia-Jia Luo, Han Pu, Xi-Wen Guan","doi":"10.1088/1361-6633/ad7b70","DOIUrl":"10.1088/1361-6633/ad7b70","url":null,"abstract":"<p><p>We present analytical results of the fundamental properties of the one-dimensional (1D) Hubbard model with a repulsive interaction. The new model results with arbitrary external fields include: (I) using the exact solutions of the Bethe ansatz equations of the Hubbard model, we first rigorously calculate the gapless spin and charge excitations, exhibiting exotic features of fractionalized spinons and holons. We then investigate the gapped excitations in terms of the spin string and thek-Λstring bound states at arbitrary driving fields, showing subtle differences in spin magnons and charge<i>η</i>-pair excitations. (II) For a high-density and high spin magnetization region, i.e. near the quadruple critical point, we further analytically obtain the thermodynamic properties, dimensionless ratios and scaling functions near quantum phase transitions. (III) Importantly, we give the general scaling functions at quantum criticality for arbitrary filling and interaction strength. These can directly apply to other integrable models. (IV) Based on the fractional excitations and the scaling laws, the spin-incoherent Luttinger liquid (SILL) with only the charge propagation mode is elucidated by the asymptotic of the two-point correlation functions with the help of conformal field theory. We also, for the first time, obtain the analytical results of the thermodynamics for the SILL. (V) Finally, to capture deeper insights into the Mott insulator and interaction-driven criticality, we further study the double occupancy and propose its associated contact and contact susceptibilities, through which an adiabatic cooling scheme based upon quantum criticality is proposed. In this scenario, we build up general relations among arbitrary external- and internal-potential-driven quantum phase transitions, providing a comprehensive understanding of quantum criticality. Our methods offer rich perspectives of quantum integrability and offer promising guidance for future experiments with interacting electrons and ultracold atoms, both with and without a lattice.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142302917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"70 years of hyperon spectroscopy: a review of strange Ξ, Ω baryons, and the spectrum of charmed and bottom baryons.","authors":"Volker Crede, John Yelton","doi":"10.1088/1361-6633/ad7610","DOIUrl":"10.1088/1361-6633/ad7610","url":null,"abstract":"<p><p>The first hyperon was discovered about 70 years ago, but the nature of these particles, particularly with regard to multistrange hyperons, and many of their properties can still be considered to be literally strange. A dedicated and successful global spectroscopy program in the 1960s and 1970s usingK-beams revealed many multistrange candidates, but the available evidence of their existence is statistically limited. For this reason, there is still much to learn about the systematics of the spectrum of excited hyperon states and what they have in common with their non-strange companions, or how they differ from the nucleon and Δ resonances. Results from photo- and electroproduction experiments off the proton and neutron using polarized beams and targets have provided intriguing evidence for new nucleon excitations and shed light on the structure of some of the known nucleon and Δ states. Recent years have also seen a great deal of progress in the field of charmed and bottom baryon spectroscopy. Unprecedented data from the Large Hadron Collider in particular indicate continued rapid progress in the field of bottom baryons. On the theoretical side, baryons with one heavy quark<i>Q</i>and a light<i>qq</i>system serve as an ideal laboratory for studying light<i>qq</i>(diquark) correlations and the dynamics of the light quarks in the colour environment of a heavy quark. In this review, we discuss the status of doubly and triply strange Ξ as well as Ω baryons, and the properties of all the known charmed and bottom states. The comparison of the two heavy sectors reveals many similarities as predicted by heavy-quark symmetries, together with differences in mass splittings easily understood by potential models. The multi-strange hyperons bridge the under-explored gap between the light- and the heavy-flavour baryons. How do the properties of a singly charmed<i>Q</i>-<i>qq</i>system change with decreasing mass of the heavy quark in the transition to a doubly strange<i>q</i>-<i>QQ</i>system with a heavier quark-quark system relative to one light quark? Significant progress towards understanding hyperon resonances is expected in coming years from the ongoing experiments at the high-energy collider facilities and planned experiments using<i>K</i>beams at Jefferson Laboratory and J-PARC.</p>","PeriodicalId":74666,"journal":{"name":"Reports on progress in physics. Physical Society (Great Britain)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142121295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}