Pub Date : 2024-12-04DOI: 10.1016/j.physrep.2024.09.004
The CMS Collaboration
The discovery of the Higgs boson has led to new possible signatures for heavy resonance searches at the LHC. Since then, search channels including at least one Higgs boson plus another particle have formed an important part of the program of new physics searches. In this report, the status of these searches by the CMS Collaboration is reviewed. Searches are discussed for resonances decaying to two Higgs bosons, a Higgs and a vector boson, or a Higgs boson and another new resonance. All analyses use proton–proton collision data collected at in the years 2016–2018. A combination of the results of these searches is presented together with constraints on different beyond-the-standard model scenarios, including scenarios with extended Higgs sectors, heavy vector bosons and extra dimensions. Studies are shown for the first time by CMS on the validity of the narrow-width approximation in searches for the resonant production of a pair of Higgs bosons. The potential for a discovery at the High Luminosity LHC is also discussed.
{"title":"Searches for Higgs boson production through decays of heavy resonances","authors":"The CMS Collaboration","doi":"10.1016/j.physrep.2024.09.004","DOIUrl":"10.1016/j.physrep.2024.09.004","url":null,"abstract":"<div><div>The discovery of the Higgs boson has led to new possible signatures for heavy resonance searches at the LHC. Since then, search channels including at least one Higgs boson plus another particle have formed an important part of the program of new physics searches. In this report, the status of these searches by the CMS Collaboration is reviewed. Searches are discussed for resonances decaying to two Higgs bosons, a Higgs and a vector boson, or a Higgs boson and another new resonance. All analyses use proton–proton collision data collected at <span><math><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mspace></mspace><mi>TeV</mi></mrow></math></span> in the years 2016–2018. A combination of the results of these searches is presented together with constraints on different beyond-the-standard model scenarios, including scenarios with extended Higgs sectors, heavy vector bosons and extra dimensions. Studies are shown for the first time by CMS on the validity of the narrow-width approximation in searches for the resonant production of a pair of Higgs bosons. The potential for a discovery at the High Luminosity LHC is also discussed.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1115 ","pages":"Pages 368-447"},"PeriodicalIF":23.9,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696019","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}
Pub Date : 2024-12-04DOI: 10.1016/j.physrep.2024.09.006
CMS Collaboration
Specialized data-taking and data-processing techniques were introduced by the CMS experiment in Run 1 of the CERN LHC to enhance the sensitivity of searches for new physics and the precision of standard model measurements. These techniques, termed data scouting and data parking, extend the data-taking capabilities of CMS beyond the original design specifications. The novel data-scouting strategy trades complete event information for higher event rates, while keeping the data bandwidth within limits. Data parking involves storing a large amount of raw detector data collected by algorithms with low trigger thresholds to be processed when sufficient computational power is available to handle such data. The research program of the CMS Collaboration is greatly expanded with these techniques. The implementation, performance, and physics results obtained with data scouting and data parking in CMS over the last decade are discussed in this Report, along with new developments aimed at further improving low-mass physics sensitivity over the next years of data taking.
{"title":"Enriching the physics program of the CMS experiment via data scouting and data parking","authors":"CMS Collaboration","doi":"10.1016/j.physrep.2024.09.006","DOIUrl":"10.1016/j.physrep.2024.09.006","url":null,"abstract":"<div><div>Specialized data-taking and data-processing techniques were introduced by the CMS experiment in Run 1 of the CERN LHC to enhance the sensitivity of searches for new physics and the precision of standard model measurements. These techniques, termed data scouting and data parking, extend the data-taking capabilities of CMS beyond the original design specifications. The novel data-scouting strategy trades complete event information for higher event rates, while keeping the data bandwidth within limits. Data parking involves storing a large amount of raw detector data collected by algorithms with low trigger thresholds to be processed when sufficient computational power is available to handle such data. The research program of the CMS Collaboration is greatly expanded with these techniques. The implementation, performance, and physics results obtained with data scouting and data parking in CMS over the last decade are discussed in this Report, along with new developments aimed at further improving low-mass physics sensitivity over the next years of data taking.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1115 ","pages":"Pages 678-772"},"PeriodicalIF":23.9,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696018","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}
Pub Date : 2024-12-02DOI: 10.1016/j.physrep.2024.11.006
Rui Tang , Ziyun Yong , Shuyu Jiang , Xingshu Chen , Yaofang Liu , Yi-Cheng Zhang , Gui-Quan Sun , Wei Wang
Complex networks are frequently employed to model physical or virtual complex systems. When certain entities exist across multiple systems simultaneously, unveiling their corresponding relationships across the networks becomes crucial. This problem, known as network alignment, holds significant importance. It enhances our understanding of complex system structures and behaviours, facilitates the validation and extension of theoretical physics research about studying complex systems, and fosters diverse practical applications across various fields. However, due to variations in the structure, characteristics, and properties of complex networks across different fields, the study of network alignment is often isolated within each domain, with even the terminologies and concepts lacking uniformity. This review comprehensively summarizes the latest advancements in network alignment research, focusing on analysing network alignment characteristics and progress in various domains such as social network analysis, bioinformatics, computational linguistics and privacy protection. It provides a detailed analysis of various methods’ implementation principles, processes, and performance differences, including structure consistency-based methods, network embedding-based methods, and graph neural network-based (GNN-based) methods. Additionally, the methods for network alignment under different conditions, such as in attributed networks, heterogeneous networks, directed networks, and dynamic networks, are presented. Furthermore, the challenges and the open issues for future studies are also discussed.
{"title":"Network alignment","authors":"Rui Tang , Ziyun Yong , Shuyu Jiang , Xingshu Chen , Yaofang Liu , Yi-Cheng Zhang , Gui-Quan Sun , Wei Wang","doi":"10.1016/j.physrep.2024.11.006","DOIUrl":"10.1016/j.physrep.2024.11.006","url":null,"abstract":"<div><div>Complex networks are frequently employed to model physical or virtual complex systems. When certain entities exist across multiple systems simultaneously, unveiling their corresponding relationships across the networks becomes crucial. This problem, known as network alignment, holds significant importance. It enhances our understanding of complex system structures and behaviours, facilitates the validation and extension of theoretical physics research about studying complex systems, and fosters diverse practical applications across various fields. However, due to variations in the structure, characteristics, and properties of complex networks across different fields, the study of network alignment is often isolated within each domain, with even the terminologies and concepts lacking uniformity. This review comprehensively summarizes the latest advancements in network alignment research, focusing on analysing network alignment characteristics and progress in various domains such as social network analysis, bioinformatics, computational linguistics and privacy protection. It provides a detailed analysis of various methods’ implementation principles, processes, and performance differences, including structure consistency-based methods, network embedding-based methods, and graph neural network-based (GNN-based) methods. Additionally, the methods for network alignment under different conditions, such as in attributed networks, heterogeneous networks, directed networks, and dynamic networks, are presented. Furthermore, the challenges and the open issues for future studies are also discussed.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1107 ","pages":"Pages 1-45"},"PeriodicalIF":23.9,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143161367","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}
Pub Date : 2024-11-20DOI: 10.1016/j.physrep.2024.11.004
Alexander M. Akulshin , Dmitry Budker , Felipe Pedreros Bustos , Tong Dang , Emmanuel Klinger , Simon M. Rochester , Arne Wickenbrock , Rui Zhang
Sensitive magnetometers have been applied in a wide range of research fields, including geophysical exploration, bio-magnetic field detection, ultralow-field nuclear magnetic resonance, etc. Commonly, magnetometers are directly placed at the position where the magnetic field is to be measured. However, in some situations, for example in near space or harsh environments, near nuclear reactors or particle accelerators, it is hard to place a magnetometer directly there. If the magnetic field can be detected remotely, i.e., via stand-off detection, this problem can be solved. As optical magnetometers are based on optical readout, they are naturally promising for stand-off detection. We review various approaches to optical stand-off magnetometry proposed and developed over the years, culminating in recent results on measuring magnetic fields in the mesosphere using laser guide stars, magnetometry with mirrorless-lasing readout, and proposals for satellite-assisted interrogation of atmospheric sodium.
{"title":"Remote detection optical magnetometry","authors":"Alexander M. Akulshin , Dmitry Budker , Felipe Pedreros Bustos , Tong Dang , Emmanuel Klinger , Simon M. Rochester , Arne Wickenbrock , Rui Zhang","doi":"10.1016/j.physrep.2024.11.004","DOIUrl":"10.1016/j.physrep.2024.11.004","url":null,"abstract":"<div><div>Sensitive magnetometers have been applied in a wide range of research fields, including geophysical exploration, bio-magnetic field detection, ultralow-field nuclear magnetic resonance, etc. Commonly, magnetometers are directly placed at the position where the magnetic field is to be measured. However, in some situations, for example in near space or harsh environments, near nuclear reactors or particle accelerators, it is hard to place a magnetometer directly there. If the magnetic field can be detected remotely, i.e., via stand-off detection, this problem can be solved. As optical magnetometers are based on optical readout, they are naturally promising for stand-off detection. We review various approaches to optical stand-off magnetometry proposed and developed over the years, culminating in recent results on measuring magnetic fields in the mesosphere using laser guide stars, magnetometry with mirrorless-lasing readout, and proposals for satellite-assisted interrogation of atmospheric sodium.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1106 ","pages":"Pages 1-32"},"PeriodicalIF":23.9,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698499","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}
Pub Date : 2024-11-19DOI: 10.1016/j.physrep.2024.11.002
Adriano Tiribocchi , Mihir Durve , Marco Lauricella , Andrea Montessori , Jean-Michel Tucny , Sauro Succi
Over the last decade, the Lattice Boltzmann method has found major scope for the simulation of a large spectrum of problems in soft matter, from multiphase and multi-component microfluidic flows, to foams, emulsions, colloidal flows, to name but a few. Crucial to many such applications is the role of supramolecular interactions which occur whenever mesoscale structures, such as bubbles or droplets, come in close contact, say of the order of tens of nanometers. Regardless of their specific physico-chemical origin, such near-contact interactions are vital to preserve the coherence of the mesoscale structures against coalescence phenomena promoted by capillarity and surface tension, hence the need of including them in Lattice Boltzmann schemes. Strictly speaking, this entails a complex multiscale problem, covering about six spatial decades, from centimeters down to tens of nanometers, and almost twice as many in time. Such a multiscale problem can hardly be taken by a single computational method, hence the need for coarse-grained models for the near-contact interactions. In this review, we shall discuss such coarse-grained models and illustrate their application to a variety of soft flowing matter problems, such as soft flowing crystals, strongly confined dense emulsions, flowing hierarchical emulsions, soft granular flows, as well as the transmigration of active droplets across constrictions. Finally, we conclude with a few considerations on future developments in the direction of quantum-nanofluidics, machine learning, and quantum computing for soft flows applications.
{"title":"Lattice Boltzmann simulations for soft flowing matter","authors":"Adriano Tiribocchi , Mihir Durve , Marco Lauricella , Andrea Montessori , Jean-Michel Tucny , Sauro Succi","doi":"10.1016/j.physrep.2024.11.002","DOIUrl":"10.1016/j.physrep.2024.11.002","url":null,"abstract":"<div><div>Over the last decade, the Lattice Boltzmann method has found major scope for the simulation of a large spectrum of problems in soft matter, from multiphase and multi-component microfluidic flows, to foams, emulsions, colloidal flows, to name but a few. Crucial to many such applications is the role of supramolecular interactions which occur whenever mesoscale structures, such as bubbles or droplets, come in close contact, say of the order of tens of nanometers. Regardless of their specific physico-chemical origin, such near-contact interactions are vital to preserve the coherence of the mesoscale structures against coalescence phenomena promoted by capillarity and surface tension, hence the need of including them in Lattice Boltzmann schemes. Strictly speaking, this entails a complex multiscale problem, covering about six spatial decades, from centimeters down to tens of nanometers, and almost twice as many in time. Such a multiscale problem can hardly be taken by a single computational method, hence the need for coarse-grained models for the near-contact interactions. In this review, we shall discuss such coarse-grained models and illustrate their application to a variety of soft flowing matter problems, such as soft flowing crystals, strongly confined dense emulsions, flowing hierarchical emulsions, soft granular flows, as well as the transmigration of active droplets across constrictions. Finally, we conclude with a few considerations on future developments in the direction of quantum-nanofluidics, machine learning, and quantum computing for soft flows applications.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1105 ","pages":"Pages 1-52"},"PeriodicalIF":23.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699144","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}
Pub Date : 2024-11-16DOI: 10.1016/j.physrep.2024.11.001
ATLAS Collaboration
The Higgs boson was discovered by the ATLAS and CMS Collaborations in 2012 using data from Run 1 of the Large Hadron Collider (20102012). In Run 2 (20152018), about 140 fb−1 of proton–proton collisions at a centre-of-mass energy of 13 TeV were collected by the ATLAS experiment. This review presents the most important Run 2 results obtained by the ATLAS Collaboration regarding the properties of the Higgs boson and its interactions with other particles. The performed studies significantly enhance the understanding of the Higgs boson, while hunting for deviations from the predictions of the Standard Model of particle physics.
{"title":"Characterising the Higgs boson with ATLAS data from the LHC Run-2","authors":"ATLAS Collaboration","doi":"10.1016/j.physrep.2024.11.001","DOIUrl":"10.1016/j.physrep.2024.11.001","url":null,"abstract":"<div><div>The Higgs boson was discovered by the ATLAS and CMS Collaborations in 2012 using data from Run 1 of the Large Hadron Collider (2010<span><math><mo>−</mo></math></span>2012). In Run 2 (2015<span><math><mo>−</mo></math></span>2018), about 140 fb<sup>−1</sup> of proton–proton collisions at a centre-of-mass energy of 13 TeV were collected by the ATLAS experiment. This review presents the most important Run 2 results obtained by the ATLAS Collaboration regarding the properties of the Higgs boson and its interactions with other particles. The performed studies significantly enhance the understanding of the Higgs boson, while hunting for deviations from the predictions of the Standard Model of particle physics.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1116 ","pages":"Pages 4-56"},"PeriodicalIF":23.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760869","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}
Pub Date : 2024-11-16DOI: 10.1016/j.physrep.2024.11.003
Karyn Le Hur
I review my recent progress and develop a geometrical approach in the quantum with light as a guide, from the vector potential in classical physics, revealing that topological properties can be equivalently measured from the poles of a sphere. The topological state is induced on the Bloch sphere of a spin-1/2 particle from a radial magnetic field related to the physics of Skyrmions. This shows a relation between the global topological response being measured at the poles, the response to a circularly polarized field and the quantum metric. I show how this approach is helpful for the classification of matter with the detection of the global topological invariant at specific points in the Brillouin zone, e.g. the Dirac points, from the responses to electromagnetic waves such as circularly polarized light and from new geometrical functions associated to the quantum metric measuring the quantum Hall and spin Hall conductivities. The point associated to the Brillouin zone of the honeycomb lattice also reveals the topological signature. Interactions are included in momentum space within a stochastic variational approach. In a realistic quantum model of interacting spins, this leads to fractional topological entangled aspects with a correspondence between a pair of half invariants and a Einstein–Podolsky–Rosen (EPR) pair or Bell state at one pole. I also formulate a correspondence between fractional topological numbers and resonating valence bond states. This approach gives further insight on the characterization of topological matter linked to superconductivity, protected topological semimetals in two dimensions and on the search of Majorana fermions for topologically protected quantum information. We also address a correspondence with the fractional quantum Hall effect and surface states of three-dimensional topological insulators.
我回顾了自己的最新进展，并从经典物理学中的矢量势出发，以光为向导，发展出一种量子几何方法，揭示了拓扑特性可以等同于从球体的两极进行测量。自旋-1/2粒子的布洛赫球上的拓扑状态是由与天幕物理学相关的径向磁场诱发的。这表明了在两极测量的全局拓扑响应、对圆极化磁场的响应和量子度量之间的关系。我将从对电磁波（如圆偏振光）的响应，以及与测量量子霍尔和自旋霍尔电导率的量子度量相关联的新几何函数中，展示这种方法如何有助于在布里渊区的特定点（如狄拉克点）检测到全局拓扑不变量，从而对物质进行分类。与蜂巢晶格布里渊区相关的 M 点也揭示了拓扑特征。在随机变异方法中，相互作用被纳入动量空间。在相互作用的自旋的现实量子模型中，这导致了分数拓扑纠缠方面，一对半不变式与一极的爱因斯坦-波多尔斯基-罗森（EPR）对或贝尔态之间存在对应关系。我还提出了分数拓扑数与共振价键态之间的对应关系。这种方法进一步揭示了与超导有关的拓扑物质的特征、二维受保护拓扑半金属以及寻找受拓扑保护的量子信息的马约拉纳费米子。我们还探讨了分数量子霍尔效应与三维拓扑绝缘体表面态的对应关系。
{"title":"Interacting topological quantum aspects with light and geometrical functions","authors":"Karyn Le Hur","doi":"10.1016/j.physrep.2024.11.003","DOIUrl":"10.1016/j.physrep.2024.11.003","url":null,"abstract":"<div><div>I review my recent progress and develop a geometrical approach in the quantum with light as a guide, from the vector potential in classical physics, revealing that topological properties can be equivalently measured from the poles of a sphere. The topological state is induced on the Bloch sphere of a spin-1/2 particle from a radial magnetic field related to the physics of Skyrmions. This shows a relation between the global topological response being measured at the poles, the response to a circularly polarized field and the quantum metric. I show how this approach is helpful for the classification of matter with the detection of the global topological invariant at specific points in the Brillouin zone, e.g. the Dirac points, from the responses to electromagnetic waves such as circularly polarized light and from new geometrical functions associated to the quantum metric measuring the quantum Hall and spin Hall conductivities. The <span><math><mi>M</mi></math></span> point associated to the Brillouin zone of the honeycomb lattice also reveals the topological signature. Interactions are included in momentum space within a stochastic variational approach. In a realistic quantum model of interacting spins, this leads to fractional topological entangled aspects with a correspondence between a pair of half invariants and a Einstein–Podolsky–Rosen (EPR) pair or Bell state at one pole. I also formulate a correspondence between fractional topological numbers and resonating valence bond states. This approach gives further insight on the characterization of topological matter linked to superconductivity, protected topological semimetals in two dimensions and on the search of Majorana fermions for topologically protected quantum information. We also address a correspondence with the fractional quantum Hall effect and surface states of three-dimensional topological insulators.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1104 ","pages":"Pages 1-42"},"PeriodicalIF":23.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657528","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}
Pub Date : 2024-11-14DOI: 10.1016/j.physrep.2024.10.008
Xiaowen Chen , Roman Adam , Daniel E. Bürgler , Fangzhou Wang , Zhenyan Lu , Lining Pan , Sarah Heidtfeld , Christian Greb , Meihong Liu , Qingfang Liu , Jianbo Wang , Claus M. Schneider , Derang Cao
Since the discovery of ultrafast demagnetization in Ni thin films in 1996, laser-induced ultrafast spin dynamics have become a prominent research topic in the field of magnetism and spintronics. This development offers new possibilities for the advancement of spintronics and magnetic storage technology. The subject has drawn a substantial number of researchers, leading to a series of research endeavors. Various models have been proposed to elucidate the physical processes underlying laser-induced ultrafast spin dynamics in ferromagnetic materials. However, the potential origins of these processes across different material systems and the true contributions of these different origins remain challenging in the realm of ultrafast spin dynamics. This predicament also hinders the development of spintronic terahertz emitters.
In this review, we initially introduce the different experimental methods used in laser-induced ultrafast spin dynamics. We then systematically explore the magnetization precession process and present seven models of ultrafast demagnetization in ferromagnetic materials. Subsequently, we discuss the physical processes and research status of four ultrafast demagnetization origins (including spin-flipping, spin transport, non-thermal electronic distribution, and laser-induced lattice strain). Since attosecond laser technique and antiferromagnetic materials exhibit promising applications in ultrahigh-frequency spintronics, we acknowledge the emerging studies used by attosecond pulses and studies on ultrafast spin dynamics in antiferromagnets, noting the significant challenges that need to be addressed in these burgeoning field.
{"title":"Ultrafast demagnetization in ferromagnetic materials: Origins and progress","authors":"Xiaowen Chen , Roman Adam , Daniel E. Bürgler , Fangzhou Wang , Zhenyan Lu , Lining Pan , Sarah Heidtfeld , Christian Greb , Meihong Liu , Qingfang Liu , Jianbo Wang , Claus M. Schneider , Derang Cao","doi":"10.1016/j.physrep.2024.10.008","DOIUrl":"10.1016/j.physrep.2024.10.008","url":null,"abstract":"<div><div>Since the discovery of ultrafast demagnetization in Ni thin films in 1996, laser-induced ultrafast spin dynamics have become a prominent research topic in the field of magnetism and spintronics. This development offers new possibilities for the advancement of spintronics and magnetic storage technology. The subject has drawn a substantial number of researchers, leading to a series of research endeavors. Various models have been proposed to elucidate the physical processes underlying laser-induced ultrafast spin dynamics in ferromagnetic materials. However, the potential origins of these processes across different material systems and the true contributions of these different origins remain challenging in the realm of ultrafast spin dynamics. This predicament also hinders the development of spintronic terahertz emitters.</div><div>In this review, we initially introduce the different experimental methods used in laser-induced ultrafast spin dynamics. We then systematically explore the magnetization precession process and present seven models of ultrafast demagnetization in ferromagnetic materials. Subsequently, we discuss the physical processes and research status of four ultrafast demagnetization origins (including spin-flipping, spin transport, non-thermal electronic distribution, and laser-induced lattice strain). Since attosecond laser technique and antiferromagnetic materials exhibit promising applications in ultrahigh-frequency spintronics, we acknowledge the emerging studies used by attosecond pulses and studies on ultrafast spin dynamics in antiferromagnets, noting the significant challenges that need to be addressed in these burgeoning field.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1102 ","pages":"Pages 1-63"},"PeriodicalIF":23.9,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653221","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}
Pub Date : 2024-11-13DOI: 10.1016/j.physrep.2024.10.007
Sayantan Choudhury , M. Sami
In this paper, we review in detail different mechanisms of generation of large primordial fluctuations and their implications for the production of primordial black holes (PBHs) and scalar-induced secondary gravity waves (SIGW), with the ultimate aim of understanding the impact of loop correction on quantum correlations and the power spectrum. To accomplish the goal, we provide a concise, comprehensive, but in depth review of conceptual and technical details of the standard model of the universe, namely, causal structure and inflation, quantization of primordial perturbations and field theoretic techniques such as “in-in” formalism needed for the estimation of loop correction to the power spectrum. We discuss at length the severe constraints (no-go) on PBH production in single-field inflation imposed by appropriately renormalized quantum loop corrections, computed while maintaining the validity of the perturbation framework and assuming sufficient inflation to address the causality problem. Thereafter, we discuss in detail the efforts to circumvent the no-go result in Galileon inflation, multiple sharp transition (MST)-induced inflation, and stochastic single field inflation using an effective field theoretic (EFT) framework applicable to a variety of models. We provide a thorough analysis of the Dynamical Renormalization Group (DRG) resummation approach, adiabatic and late-time renormalization schemes, and their use in producing solar and sub-solar mass PBHs. Additionally, we give a summary of how scalar-induced gravitational waves (SIGWs) are produced in MST setups and Galileon inflation. Finally, the PBH overproduction issue is thoroughly discussed.
{"title":"Large fluctuations and primordial black holes","authors":"Sayantan Choudhury , M. Sami","doi":"10.1016/j.physrep.2024.10.007","DOIUrl":"10.1016/j.physrep.2024.10.007","url":null,"abstract":"<div><div>In this paper, we review in detail different mechanisms of generation of large primordial fluctuations and their implications for the production of primordial black holes (PBHs) and scalar-induced secondary gravity waves (SIGW), with the ultimate aim of understanding the impact of loop correction on quantum correlations and the power spectrum. To accomplish the goal, we provide a concise, comprehensive, but in depth review of conceptual and technical details of the standard model of the universe, namely, causal structure and inflation, quantization of primordial perturbations and field theoretic techniques such as “in-in” formalism needed for the estimation of loop correction to the power spectrum. We discuss at length the severe constraints (no-go) on PBH production in single-field inflation imposed by appropriately renormalized quantum loop corrections, computed while maintaining the validity of the perturbation framework and assuming sufficient inflation to address the causality problem. Thereafter, we discuss in detail the efforts to circumvent the no-go result in Galileon inflation, multiple sharp transition (MST)-induced inflation, and stochastic single field inflation using an effective field theoretic (EFT) framework applicable to a variety of models. We provide a thorough analysis of the Dynamical Renormalization Group (DRG) resummation approach, adiabatic and late-time renormalization schemes, and their use in producing solar and sub-solar mass PBHs. Additionally, we give a summary of how scalar-induced gravitational waves (SIGWs) are produced in MST setups and Galileon inflation. Finally, the PBH overproduction issue is thoroughly discussed.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1103 ","pages":"Pages 1-276"},"PeriodicalIF":23.9,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664028","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}
Pub Date : 2024-11-07DOI: 10.1016/j.physrep.2024.10.005
Stephan Rachel , Roland Wiesendanger
For the past decade, Majorana quasiparticles have become one of the hot topics in condensed matter research. Besides the fundamental interest in the realization of particles being their own antiparticles, going back to basic concepts of elementary particle physics, Majorana quasiparticles in condensed matter systems offer exciting potential applications in topological quantum computation due to their non-Abelian quantum exchange statistics. Motivated by theoretical predictions about possible realizations of Majorana quasiparticles as zero-energy modes at boundaries of topological superconductors, experimental efforts have focussed in particular on quasi-one-dimensional semiconductor–superconductor and magnet–superconductor hybrid systems. However, an unambiguous proof of the existence of Majorana quasiparticles is still challenging and requires considerable improvements in materials science, atomic-scale characterization and control of interface quality, as well as complementary approaches of detecting various facets of Majorana quasiparticles. Bottom-up atom-by-atom fabrication of disorder-free atomic spin chains on atomically clean superconducting substrates has recently allowed deep insight into the emergence of topological sub-gap Shiba bands and associated Majorana states from the level of individual atoms up to extended chains, thereby offering the possibility for critical tests of Majorana physics in disorder-free model-type 1D hybrid systems.
{"title":"Majorana quasiparticles in atomic spin chains on superconductors","authors":"Stephan Rachel , Roland Wiesendanger","doi":"10.1016/j.physrep.2024.10.005","DOIUrl":"10.1016/j.physrep.2024.10.005","url":null,"abstract":"<div><div>For the past decade, Majorana quasiparticles have become one of the hot topics in condensed matter research. Besides the fundamental interest in the realization of particles being their own antiparticles, going back to basic concepts of elementary particle physics, Majorana quasiparticles in condensed matter systems offer exciting potential applications in topological quantum computation due to their non-Abelian quantum exchange statistics. Motivated by theoretical predictions about possible realizations of Majorana quasiparticles as zero-energy modes at boundaries of topological superconductors, experimental efforts have focussed in particular on quasi-one-dimensional semiconductor–superconductor and magnet–superconductor hybrid systems. However, an unambiguous proof of the existence of Majorana quasiparticles is still challenging and requires considerable improvements in materials science, atomic-scale characterization and control of interface quality, as well as complementary approaches of detecting various facets of Majorana quasiparticles. Bottom-up atom-by-atom fabrication of disorder-free atomic spin chains on atomically clean superconducting substrates has recently allowed deep insight into the emergence of topological sub-gap Shiba bands and associated Majorana states from the level of individual atoms up to extended chains, thereby offering the possibility for critical tests of Majorana physics in disorder-free model-type 1D hybrid systems.</div></div>","PeriodicalId":404,"journal":{"name":"Physics Reports","volume":"1099 ","pages":"Pages 1-28"},"PeriodicalIF":23.9,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658262","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}
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