Pub Date : 2018-10-02DOI: 10.1080/00018732.2019.1594094
Dan-Wei Zhang, Yan-Qing Zhu, Y. Zhao, Hui Yan, Shi-Liang Zhu
This is an introductory review of the physics of topological quantum matter with cold atoms. Topological quantum phases, originally discovered and investigated in condensed matter physics, have recently been explored in a range of different systems, which produced both fascinating physics findings and exciting opportunities for applications. Among the physical systems that have been considered to realize and probe these intriguing phases, ultracold atoms become promising platforms due to their high flexibility and controllability. Quantum simulation of topological phases with cold atomic gases is a rapidly evolving field, and recent theoretical and experimental developments reveal that some toy models originally proposed in condensed matter physics have been realized with this artificial quantum system. The purpose of this article is to introduce these developments. The article begins with a tutorial review of topological invariants and the methods to control parameters in the Hamiltonians of neutral atoms. Next, topological quantum phases in optical lattices are introduced in some detail, especially several celebrated models, such as the Su–Schrieffer–Heeger model, the Hofstadter–Harper model, the Haldane model and the Kane–Mele model. The theoretical proposals and experimental implementations of these models are discussed. Notably, many of these models cannot be directly realized in conventional solid-state experiments. The newly developed methods for probing the intrinsic properties of the topological phases in cold-atom systems are also reviewed. Finally, some topological phases with cold atoms in the continuum and in the presence of interactions are discussed, and an outlook on future work is given.
{"title":"Topological quantum matter with cold atoms","authors":"Dan-Wei Zhang, Yan-Qing Zhu, Y. Zhao, Hui Yan, Shi-Liang Zhu","doi":"10.1080/00018732.2019.1594094","DOIUrl":"https://doi.org/10.1080/00018732.2019.1594094","url":null,"abstract":"This is an introductory review of the physics of topological quantum matter with cold atoms. Topological quantum phases, originally discovered and investigated in condensed matter physics, have recently been explored in a range of different systems, which produced both fascinating physics findings and exciting opportunities for applications. Among the physical systems that have been considered to realize and probe these intriguing phases, ultracold atoms become promising platforms due to their high flexibility and controllability. Quantum simulation of topological phases with cold atomic gases is a rapidly evolving field, and recent theoretical and experimental developments reveal that some toy models originally proposed in condensed matter physics have been realized with this artificial quantum system. The purpose of this article is to introduce these developments. The article begins with a tutorial review of topological invariants and the methods to control parameters in the Hamiltonians of neutral atoms. Next, topological quantum phases in optical lattices are introduced in some detail, especially several celebrated models, such as the Su–Schrieffer–Heeger model, the Hofstadter–Harper model, the Haldane model and the Kane–Mele model. The theoretical proposals and experimental implementations of these models are discussed. Notably, many of these models cannot be directly realized in conventional solid-state experiments. The newly developed methods for probing the intrinsic properties of the topological phases in cold-atom systems are also reviewed. Finally, some topological phases with cold atoms in the continuum and in the presence of interactions are discussed, and an outlook on future work is given.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"67 1","pages":"253 - 402"},"PeriodicalIF":0.0,"publicationDate":"2018-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2019.1594094","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42582933","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 : 2018-06-28DOI: 10.1080/00018732.2018.1571986
D. Inosov
The discovery of magnetism by the ancient Greeks was enabled by the natural occurrence of lodestone – a magnetized version of the mineral magnetite. Nowadays, natural minerals continue to inspire the search for novel magnetic materials with quantum-critical behaviour or exotic ground states such as spin liquids. The recent surge of interest in magnetic frustration and quantum magnetism was largely encouraged by crystalline structures of natural minerals realizing pyrochlore, kagome, or triangular arrangements of magnetic ions. As a result, names like azurite, jarosite, volborthite, and others, which were barely known beyond the mineralogical community a few decades ago, found their way into cutting-edge research in solid-state physics. In some cases, the structures of natural minerals are too complex to be synthesized artificially in a chemistry lab, especially in single-crystalline form, and there is a growing number of examples demonstrating the potential of natural specimens for experimental investigations in the field of quantum magnetism. On many other occasions, minerals may guide chemists in the synthesis of novel compounds with unusual magnetic properties. The present review attempts to embrace this quickly emerging interdisciplinary field that bridges mineralogy with low-temperature condensed-matter physics and quantum chemistry.
{"title":"Quantum magnetism in minerals","authors":"D. Inosov","doi":"10.1080/00018732.2018.1571986","DOIUrl":"https://doi.org/10.1080/00018732.2018.1571986","url":null,"abstract":"The discovery of magnetism by the ancient Greeks was enabled by the natural occurrence of lodestone – a magnetized version of the mineral magnetite. Nowadays, natural minerals continue to inspire the search for novel magnetic materials with quantum-critical behaviour or exotic ground states such as spin liquids. The recent surge of interest in magnetic frustration and quantum magnetism was largely encouraged by crystalline structures of natural minerals realizing pyrochlore, kagome, or triangular arrangements of magnetic ions. As a result, names like azurite, jarosite, volborthite, and others, which were barely known beyond the mineralogical community a few decades ago, found their way into cutting-edge research in solid-state physics. In some cases, the structures of natural minerals are too complex to be synthesized artificially in a chemistry lab, especially in single-crystalline form, and there is a growing number of examples demonstrating the potential of natural specimens for experimental investigations in the field of quantum magnetism. On many other occasions, minerals may guide chemists in the synthesis of novel compounds with unusual magnetic properties. The present review attempts to embrace this quickly emerging interdisciplinary field that bridges mineralogy with low-temperature condensed-matter physics and quantum chemistry.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"67 1","pages":"149 - 252"},"PeriodicalIF":0.0,"publicationDate":"2018-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2018.1571986","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44774271","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 : 2018-04-03DOI: 10.1080/00018732.2018.1551715
J. Mao, Zihang Liu, Jiawei Zhou, Hangtian Zhu, Qian Zhang, Gang Chen, Z. Ren
Thermoelectric generators, capable of directly converting heat into electricity, hold great promise for tackling the ever-increasing energy sustainability issue. The thermoelectric energy conversion efficiency is heavily dependent upon the materials’ performance that is quantified by the dimensionless figure-of-merit (ZT). Therefore, the central issue in the research of thermoelectric materials lies in continuously boosting the ZT value. Although thermoelectric effects were discovered in the nineteenth century, it was only until the 1950s when classic materials like Bi2Te3 and PbTe were developed and basic science of thermoelectrics was established. However, the research of thermoelectrics did not take a smooth path but a rather tortuous one with ups and downs. After hiatus in the 1970s and 1980s, relentless efforts starting from the 1990s were devoted to understanding the transport and coupling of electrons and phonons, identifying strategies for improving the thermoelectric performance of existing materials, and discovering new promising compounds. Rewardingly, substantial improvements in materials’ performance have been achieved that broke the ZT limit of unity. Meanwhile, advancements in fundamental understanding related to thermoelectrics have also been made. In this Review, recent advances in the research of thermoelectric materials are overviewed. Herein, strategies for improving and decoupling the individual thermoelectric parameters are first reviewed, together with a discussion on open questions and distinctly different opinions. Recent advancements on a number of good thermoelectric materials are highlighted and several newly discovered promising compounds are discussed. Existing challenges in the research of thermoelectric materials are outlined and an outlook for the future thermoelectrics research is presented. The paper concludes with a discussion of topics in other fields but related to thermoelectricity.
{"title":"Advances in thermoelectrics","authors":"J. Mao, Zihang Liu, Jiawei Zhou, Hangtian Zhu, Qian Zhang, Gang Chen, Z. Ren","doi":"10.1080/00018732.2018.1551715","DOIUrl":"https://doi.org/10.1080/00018732.2018.1551715","url":null,"abstract":"Thermoelectric generators, capable of directly converting heat into electricity, hold great promise for tackling the ever-increasing energy sustainability issue. The thermoelectric energy conversion efficiency is heavily dependent upon the materials’ performance that is quantified by the dimensionless figure-of-merit (ZT). Therefore, the central issue in the research of thermoelectric materials lies in continuously boosting the ZT value. Although thermoelectric effects were discovered in the nineteenth century, it was only until the 1950s when classic materials like Bi2Te3 and PbTe were developed and basic science of thermoelectrics was established. However, the research of thermoelectrics did not take a smooth path but a rather tortuous one with ups and downs. After hiatus in the 1970s and 1980s, relentless efforts starting from the 1990s were devoted to understanding the transport and coupling of electrons and phonons, identifying strategies for improving the thermoelectric performance of existing materials, and discovering new promising compounds. Rewardingly, substantial improvements in materials’ performance have been achieved that broke the ZT limit of unity. Meanwhile, advancements in fundamental understanding related to thermoelectrics have also been made. In this Review, recent advances in the research of thermoelectric materials are overviewed. Herein, strategies for improving and decoupling the individual thermoelectric parameters are first reviewed, together with a discussion on open questions and distinctly different opinions. Recent advancements on a number of good thermoelectric materials are highlighted and several newly discovered promising compounds are discussed. Existing challenges in the research of thermoelectric materials are outlined and an outlook for the future thermoelectrics research is presented. The paper concludes with a discussion of topics in other fields but related to thermoelectricity.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"67 1","pages":"69 - 147"},"PeriodicalIF":0.0,"publicationDate":"2018-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2018.1551715","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46096747","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 : 2017-10-02DOI: 10.1080/00018732.2017.1466475
J. Mydosh
Magnetic fields are now available to 100 T (pulsed), 45 T (static) at temperatures below 0.3 K. Such technical developments allow the study and tuning of (quantum) phase transitions, unusual magnetic structures and (high-temperature) superconductors in a variety of quantum materials. An especially important class of strongly correlated electron materials is the heavy Fermi liquids (HFLs) displaying numerous reduced-moment antiferromagnets, quantum critical points, unconventional superconductivity, hidden order (HO) and other mysterious ground states. Among the ‘heavy fermions’, the duality of 5f electrons in uranium-based compounds introduces interesting behavior that can be affected by large magnetic fields. I list a few such heavy fermion materials to be considered: URu2Si2 and its tunable hidden state, UBe13 and UPt3 as very HFL paramagnets that become superconducting, the magnetic superconductors UPd2Al3 and UNi2Al3, and the ferromagnetic s UGe2, URhGe and UCoGe. There are also the suggested metamagnetic Fermi-surface reconstructed intermetallic compounds such as UPt2Si2 and UCo2Si2. Present research attention focuses on the high-field behavior (30–40 T) of URu2Si2 and its destruction of HO. These and other U-based systems, e.g. UAu2Si2, UIrGe, etc., expand the opportunities of high magnetic field studies far into the future.
{"title":"High magnetic field behavior of strongly correlated uranium-based compounds","authors":"J. Mydosh","doi":"10.1080/00018732.2017.1466475","DOIUrl":"https://doi.org/10.1080/00018732.2017.1466475","url":null,"abstract":"Magnetic fields are now available to 100 T (pulsed), 45 T (static) at temperatures below 0.3 K. Such technical developments allow the study and tuning of (quantum) phase transitions, unusual magnetic structures and (high-temperature) superconductors in a variety of quantum materials. An especially important class of strongly correlated electron materials is the heavy Fermi liquids (HFLs) displaying numerous reduced-moment antiferromagnets, quantum critical points, unconventional superconductivity, hidden order (HO) and other mysterious ground states. Among the ‘heavy fermions’, the duality of 5f electrons in uranium-based compounds introduces interesting behavior that can be affected by large magnetic fields. I list a few such heavy fermion materials to be considered: URu2Si2 and its tunable hidden state, UBe13 and UPt3 as very HFL paramagnets that become superconducting, the magnetic superconductors UPd2Al3 and UNi2Al3, and the ferromagnetic s UGe2, URhGe and UCoGe. There are also the suggested metamagnetic Fermi-surface reconstructed intermetallic compounds such as UPt2Si2 and UCo2Si2. Present research attention focuses on the high-field behavior (30–40 T) of URu2Si2 and its destruction of HO. These and other U-based systems, e.g. UAu2Si2, UIrGe, etc., expand the opportunities of high magnetic field studies far into the future.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"66 1","pages":"263 - 314"},"PeriodicalIF":0.0,"publicationDate":"2017-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2017.1466475","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44964199","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 : 2017-07-25DOI: 10.1080/00018732.2018.1519981
Daniel Manzano, Pablo I. Hurtado
Controlling transport in quantum systems holds the key to many promising quantum technologies. Here we review the power of symmetry as a resource to manipulate quantum transport and apply these ideas to engineer novel quantum devices. Using tools from open quantum systems and large deviation theory, we show that symmetry-mediated control of transport is enabled by a pair of twin dynamic phase transitions in current statistics, accompanied by a coexistence of different transport channels. By playing with the symmetry decomposition of the initial state, one can modulate the importance of the different transport channels and hence control the flowing current. Motivated by the problem of energy harvesting, we illustrate these ideas in open quantum networks, an analysis that leads to the design of a symmetry-controlled quantum thermal switch. We review an experimental setup recently proposed for symmetry-mediated quantum control in the lab based on a linear array of atom-doped optical cavities, and the possibility of using transport as a probe to uncover hidden symmetries, as recently demonstrated in molecular junctions, is also discussed. Other symmetry-mediated control mechanisms are also described. Overall, these results demonstrate the importance of symmetry not only as an organizing principle in physics but also as a tool to control quantum systems.
{"title":"Harnessing symmetry to control quantum transport","authors":"Daniel Manzano, Pablo I. Hurtado","doi":"10.1080/00018732.2018.1519981","DOIUrl":"https://doi.org/10.1080/00018732.2018.1519981","url":null,"abstract":"Controlling transport in quantum systems holds the key to many promising quantum technologies. Here we review the power of symmetry as a resource to manipulate quantum transport and apply these ideas to engineer novel quantum devices. Using tools from open quantum systems and large deviation theory, we show that symmetry-mediated control of transport is enabled by a pair of twin dynamic phase transitions in current statistics, accompanied by a coexistence of different transport channels. By playing with the symmetry decomposition of the initial state, one can modulate the importance of the different transport channels and hence control the flowing current. Motivated by the problem of energy harvesting, we illustrate these ideas in open quantum networks, an analysis that leads to the design of a symmetry-controlled quantum thermal switch. We review an experimental setup recently proposed for symmetry-mediated quantum control in the lab based on a linear array of atom-doped optical cavities, and the possibility of using transport as a probe to uncover hidden symmetries, as recently demonstrated in molecular junctions, is also discussed. Other symmetry-mediated control mechanisms are also described. Overall, these results demonstrate the importance of symmetry not only as an organizing principle in physics but also as a tool to control quantum systems.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"67 1","pages":"1 - 67"},"PeriodicalIF":0.0,"publicationDate":"2017-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2018.1519981","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46319364","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 : 2017-04-03DOI: 10.1080/00018732.2017.1331615
G. Stewart
‘Conventional’ superconductivity, as used in this review, refers to electron–phonon-coupled superconducting electron pairs described by BCS theory. Unconventional superconductivity refers to superconductors where the Cooper pairs are not bound together by phonon exchange but instead by exchange of some other kind, e.g. spin fluctuations in a superconductor with magnetic order either coexistent or nearby in the phase diagram. Such unconventional superconductivity has been known experimentally since heavy fermion CeCu2Si2, with its strongly correlated 4f electrons, was discovered to superconduct below 0.6 K in 1979. Since the discovery of unconventional superconductivity in the layered cuprates in 1986, the study of these materials saw Tc jump to 164 K by 1994. Further progress in high-temperature superconductivity would be aided by understanding the cause of such unconventional pairing. This review compares the fundamental properties of 9 unconventional superconducting classes of materials – from 4f-electron heavy fermions to organic superconductors to classes where only three known members exist to the cuprates with over 200 examples – with the hope that common features will emerge to help theory explain (and predict!) these phenomena. In addition, three new emerging classes of superconductors (topological, interfacial – e.g. FeSe on SrTiO3, and H2S under high pressure) are briefly covered, even though their ‘conventionality’ is not yet fully determined.
{"title":"Unconventional superconductivity","authors":"G. Stewart","doi":"10.1080/00018732.2017.1331615","DOIUrl":"https://doi.org/10.1080/00018732.2017.1331615","url":null,"abstract":"‘Conventional’ superconductivity, as used in this review, refers to electron–phonon-coupled superconducting electron pairs described by BCS theory. Unconventional superconductivity refers to superconductors where the Cooper pairs are not bound together by phonon exchange but instead by exchange of some other kind, e.g. spin fluctuations in a superconductor with magnetic order either coexistent or nearby in the phase diagram. Such unconventional superconductivity has been known experimentally since heavy fermion CeCu2Si2, with its strongly correlated 4f electrons, was discovered to superconduct below 0.6 K in 1979. Since the discovery of unconventional superconductivity in the layered cuprates in 1986, the study of these materials saw Tc jump to 164 K by 1994. Further progress in high-temperature superconductivity would be aided by understanding the cause of such unconventional pairing. This review compares the fundamental properties of 9 unconventional superconducting classes of materials – from 4f-electron heavy fermions to organic superconductors to classes where only three known members exist to the cuprates with over 200 examples – with the hope that common features will emerge to help theory explain (and predict!) these phenomena. In addition, three new emerging classes of superconductors (topological, interfacial – e.g. FeSe on SrTiO3, and H2S under high pressure) are briefly covered, even though their ‘conventionality’ is not yet fully determined.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"66 1","pages":"196 - 75"},"PeriodicalIF":0.0,"publicationDate":"2017-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2017.1331615","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49149121","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 : 2017-02-06DOI: 10.1080/00018732.2017.1341604
H. Nguyen, R. Zecchina, J. Berg
Inverse problems in statistical physics are motivated by the challenges of ‘big data’ in different fields, in particular high-throughput experiments in biology. In inverse problems, the usual procedure of statistical physics needs to be reversed: Instead of calculating observables on the basis of model parameters, we seek to infer parameters of a model based on observations. In this review, we focus on the inverse Ising problem and closely related problems, namely how to infer the coupling strengths between spins given observed spin correlations, magnetizations, or other data. We review applications of the inverse Ising problem, including the reconstruction of neural connections, protein structure determination, and the inference of gene regulatory networks. For the inverse Ising problem in equilibrium, a number of controlled and uncontrolled approximate solutions have been developed in the statistical mechanics community. A particularly strong method, pseudolikelihood, stems from statistics. We also review the inverse Ising problem in the non-equilibrium case, where the model parameters must be reconstructed based on non-equilibrium statistics.
{"title":"Inverse statistical problems: from the inverse Ising problem to data science","authors":"H. Nguyen, R. Zecchina, J. Berg","doi":"10.1080/00018732.2017.1341604","DOIUrl":"https://doi.org/10.1080/00018732.2017.1341604","url":null,"abstract":"Inverse problems in statistical physics are motivated by the challenges of ‘big data’ in different fields, in particular high-throughput experiments in biology. In inverse problems, the usual procedure of statistical physics needs to be reversed: Instead of calculating observables on the basis of model parameters, we seek to infer parameters of a model based on observations. In this review, we focus on the inverse Ising problem and closely related problems, namely how to infer the coupling strengths between spins given observed spin correlations, magnetizations, or other data. We review applications of the inverse Ising problem, including the reconstruction of neural connections, protein structure determination, and the inference of gene regulatory networks. For the inverse Ising problem in equilibrium, a number of controlled and uncontrolled approximate solutions have been developed in the statistical mechanics community. A particularly strong method, pseudolikelihood, stems from statistics. We also review the inverse Ising problem in the non-equilibrium case, where the model parameters must be reconstructed based on non-equilibrium statistics.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"66 1","pages":"197 - 261"},"PeriodicalIF":0.0,"publicationDate":"2017-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2017.1341604","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45107631","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 : 2017-01-02DOI: 10.1080/00018732.2017.1317963
C. Andreani, M. Krzystyniak, G. Romanelli, R. Senesi, F. Fernandez-Alonso
This work provides an up-to-date account of the use of electron-volt neutron spectroscopy in materials research. This is a growing area of neutron science, capitalising upon the unique insights provided by epithermal neutrons on the behaviour and properties of an increasing number of complex materials. As such, the present work builds upon the aims and scope of a previous contribution to this journal back in 2005, whose primary focus was on a detailed description of the theoretical foundations of the technique and their application to fundamental systems [see Andreani et al., Adv. Phys. 54 (2005) p.377] A lot has happened since then, and this review intends to capture such progress in the field. With both expert and novice in mind, we start by presenting the general principles underpinning the technique and discuss recent conceptual and methodological developments. We emphasise the increasing use of the technique as a non-invasive spectroscopic probe with intrinsic mass selectivity, as well as the concurrent use of neutron diffraction and first-principles computational materials modelling to guide and interpret experiments. To illustrate the state of the art, we discuss in detail a number of recent exemplars, chosen to highlight the use of electron-volt neutron spectroscopy across physics, chemistry, biology, and materials science. These include: hydrides and proton conductors for energy applications; protons, deuterons, and oxygen atoms in bulk water; aqueous protons confined in nanoporous silicas, carbon nanotubes, and graphene-related materials; hydrated water in proteins and DNA; and the uptake of molecular hydrogen by soft nanostructured media, promising materials for energy-storage applications. For the primary benefit of the novice, this last case study is presented in a pedagogical and question-driven fashion, in the hope that it will stimulate further work into uncharted territory by newcomers to the field. All along, we emphasise the increasing (and much-needed) synergy between experiments using electron-volt neutrons and contemporary condensed matter theory and materials modelling to compute and ultimately understand neutron-scattering observables, as well as their relation to materials properties not amenable to scrutiny using other experimental probes.
这项工作提供了电子伏特中子光谱学在材料研究中的最新应用。这是中子科学的一个不断发展的领域,利用超热中子对越来越多的复杂材料的行为和性质提供的独特见解。因此,目前的工作建立在2005年本刊前一篇文章的目标和范围之上,该文章的主要重点是详细描述该技术的理论基础及其在基本系统中的应用[见Andreani et al., Adv. Phys. 54 (2005) p.377]从那时起发生了很多事情,这篇综述旨在捕捉该领域的进展。考虑到专家和新手,我们首先介绍支撑该技术的一般原则,并讨论最近的概念和方法发展。我们强调越来越多地使用该技术作为具有内在质量选择性的非侵入性光谱探针,以及同时使用中子衍射和第一性原理计算材料建模来指导和解释实验。为了说明技术的现状,我们详细讨论了一些最近的例子,选择突出电子伏特中子光谱在物理,化学,生物学和材料科学中的应用。这些包括:用于能源应用的氢化物和质子导体;散装水中的质子、氘核和氧原子;水质子限制在纳米多孔硅,碳纳米管和石墨烯相关材料;蛋白质和DNA中的水合水;而软纳米结构介质对分子氢的吸收,是储能应用的有前途的材料。为了新手的主要利益,最后一个案例研究以教学和问题驱动的方式呈现,希望它将刺激新来者进入未知领域的进一步工作。一直以来,我们强调使用电子伏特中子和当代凝聚态理论和材料建模的实验之间日益增加的(和急需的)协同作用,以计算并最终理解中子散射可观测值,以及它们与材料特性的关系,这些特性不适合使用其他实验探针进行审查。
{"title":"Electron-volt neutron spectroscopy: beyond fundamental systems","authors":"C. Andreani, M. Krzystyniak, G. Romanelli, R. Senesi, F. Fernandez-Alonso","doi":"10.1080/00018732.2017.1317963","DOIUrl":"https://doi.org/10.1080/00018732.2017.1317963","url":null,"abstract":"This work provides an up-to-date account of the use of electron-volt neutron spectroscopy in materials research. This is a growing area of neutron science, capitalising upon the unique insights provided by epithermal neutrons on the behaviour and properties of an increasing number of complex materials. As such, the present work builds upon the aims and scope of a previous contribution to this journal back in 2005, whose primary focus was on a detailed description of the theoretical foundations of the technique and their application to fundamental systems [see Andreani et al., Adv. Phys. 54 (2005) p.377] A lot has happened since then, and this review intends to capture such progress in the field. With both expert and novice in mind, we start by presenting the general principles underpinning the technique and discuss recent conceptual and methodological developments. We emphasise the increasing use of the technique as a non-invasive spectroscopic probe with intrinsic mass selectivity, as well as the concurrent use of neutron diffraction and first-principles computational materials modelling to guide and interpret experiments. To illustrate the state of the art, we discuss in detail a number of recent exemplars, chosen to highlight the use of electron-volt neutron spectroscopy across physics, chemistry, biology, and materials science. These include: hydrides and proton conductors for energy applications; protons, deuterons, and oxygen atoms in bulk water; aqueous protons confined in nanoporous silicas, carbon nanotubes, and graphene-related materials; hydrated water in proteins and DNA; and the uptake of molecular hydrogen by soft nanostructured media, promising materials for energy-storage applications. For the primary benefit of the novice, this last case study is presented in a pedagogical and question-driven fashion, in the hope that it will stimulate further work into uncharted territory by newcomers to the field. All along, we emphasise the increasing (and much-needed) synergy between experiments using electron-volt neutrons and contemporary condensed matter theory and materials modelling to compute and ultimately understand neutron-scattering observables, as well as their relation to materials properties not amenable to scrutiny using other experimental probes.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"66 1","pages":"1 - 73"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2017.1317963","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41676523","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}
Radicular cyst (RC) is the most common odontogenic cyst of inflammatory origin affecting the jaws; involves the roots of the carious or traumatic non-vital tooth. Different therapeutic modalities, such as nonsurgical endodontic therapy or surgical enucleation with primary closure, decompression etc., were proposed for the management of such lesions. Presenting a case of a 28-year-old otherwise healthy male patient who reported with pain and swelling with respect to tooth #41, 31. Diagnosis of infected RC at a rare location was established on the basis of clinical, radiographical and fine needle aspiration cytological examination. Looking after the clinical characteristics, origin, extension, size of cystic lesion and patient cooperation; nonsurgical endodontic therapy utilizing Bhasker's hypothesis was opted. One year post-operative result suggested that nonsurgical endodontic therapy along with minimally invasive treatment utilizing Bhasker's hypothesis is an effective tool to transform infected radicular cystic lesion to healthy periapical periodontal tissue.
{"title":"Nonsurgical endodontic therapy along with minimal invasive treatment utilizing Bhasker's hypothesis for the management of infected radicular cystic lesion: A rare case report.","authors":"Sanjeev Kumar Salaria, Shilpa Kamra, Simrat Kaur Ghuman, Garima Sharma","doi":"10.4103/0976-237X.194098","DOIUrl":"10.4103/0976-237X.194098","url":null,"abstract":"<p><p>Radicular cyst (RC) is the most common odontogenic cyst of inflammatory origin affecting the jaws; involves the roots of the carious or traumatic non-vital tooth. Different therapeutic modalities, such as nonsurgical endodontic therapy or surgical enucleation with primary closure, decompression etc., were proposed for the management of such lesions. Presenting a case of a 28-year-old otherwise healthy male patient who reported with pain and swelling with respect to tooth #41, 31. Diagnosis of infected RC at a rare location was established on the basis of clinical, radiographical and fine needle aspiration cytological examination. Looking after the clinical characteristics, origin, extension, size of cystic lesion and patient cooperation; nonsurgical endodontic therapy utilizing Bhasker's hypothesis was opted. One year post-operative result suggested that nonsurgical endodontic therapy along with minimally invasive treatment utilizing Bhasker's hypothesis is an effective tool to transform infected radicular cystic lesion to healthy periapical periodontal tissue.</p>","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"5 1","pages":"562-565"},"PeriodicalIF":1.2,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5141677/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80788193","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 : 2016-09-28DOI: 10.1080/00018732.2016.1226804
Jinwei Gao, K. Kempa, M. Giersig, E. Akinoglu, B. Han, Ruopeng Li
Transparent conductors (TCs) are materials, which are characterized by high transmission of light and simultaneously very high electrical DC conductivity. These materials play a crucial role, and made possible numerous applications in the fields of electro-optics, plasmonics, biosensing, medicine, and “green energy”. Modern applications, for example in the field of touchscreen and flexible displays, require that TCs are also mechanically strong and flexible. TC can be broadly classified into two categories: uniform and non-uniform TC. The uniform TC can be viewed as conventional metals (or electron plasmas) with plasma frequency located in the infrared frequency range (e.g. transparent conducting oxides), or ultra-thin metals with large plasma frequency (e.g. graphen). The physics of the nonuniform TC is much more complex, and could involve transmission enhancement due to refraction (including plasmonic), and exotic effects of electron transport, including percolation and fractal effects. This review ties the TC performance to the underlying physical phenomena. We begin with the theoretical basis for studying the various phenomena encountered in TC. Next, we consider the uniform TC, and discuss first the conventional conducting oxides (such as indium tin oxide), reviewing advantages and limitations of these classic uniform electron plasmas. Next, we discuss the potential of single- and multiple-layer graphene as uniform TC. In the part of the paper dealing with non-uniform metallic films, we begin with the review of random metallic networks. The transparency of these networks could be enhanced beyond the classical shading limit by the plasmonic refractive effects. The electrical conduction strongly depends on the network type, and we review first networks made of individual metallic nanowires, where conductivity depends on the inter-wire contact, and the percolation effects. Next, we review the uniform metallic film networks, which are free of the percolation effects and contact problems. In applications that require high-quality electric contact of a TC to an active substrate (such as LED or solar cells), the network performance can be optimized by employing a quasi-fractal structure of the network. We also consider the periodic metallic networks, where active plasmonic refraction leads to the phenomenon of the extraordinary optical transmission. We review the relevant literature on this topic, and demonstrate networks, which take advantage of this strategy (the bio-inspired leaf venation (LV) network, hybrid networks, etc.). Finally, we review “smart” TCs, with an added functionality, such as light interference, metamaterial effects, built-in semiconductors, and their junctions.
{"title":"Physics of transparent conductors","authors":"Jinwei Gao, K. Kempa, M. Giersig, E. Akinoglu, B. Han, Ruopeng Li","doi":"10.1080/00018732.2016.1226804","DOIUrl":"https://doi.org/10.1080/00018732.2016.1226804","url":null,"abstract":"Transparent conductors (TCs) are materials, which are characterized by high transmission of light and simultaneously very high electrical DC conductivity. These materials play a crucial role, and made possible numerous applications in the fields of electro-optics, plasmonics, biosensing, medicine, and “green energy”. Modern applications, for example in the field of touchscreen and flexible displays, require that TCs are also mechanically strong and flexible. TC can be broadly classified into two categories: uniform and non-uniform TC. The uniform TC can be viewed as conventional metals (or electron plasmas) with plasma frequency located in the infrared frequency range (e.g. transparent conducting oxides), or ultra-thin metals with large plasma frequency (e.g. graphen). The physics of the nonuniform TC is much more complex, and could involve transmission enhancement due to refraction (including plasmonic), and exotic effects of electron transport, including percolation and fractal effects. This review ties the TC performance to the underlying physical phenomena. We begin with the theoretical basis for studying the various phenomena encountered in TC. Next, we consider the uniform TC, and discuss first the conventional conducting oxides (such as indium tin oxide), reviewing advantages and limitations of these classic uniform electron plasmas. Next, we discuss the potential of single- and multiple-layer graphene as uniform TC. In the part of the paper dealing with non-uniform metallic films, we begin with the review of random metallic networks. The transparency of these networks could be enhanced beyond the classical shading limit by the plasmonic refractive effects. The electrical conduction strongly depends on the network type, and we review first networks made of individual metallic nanowires, where conductivity depends on the inter-wire contact, and the percolation effects. Next, we review the uniform metallic film networks, which are free of the percolation effects and contact problems. In applications that require high-quality electric contact of a TC to an active substrate (such as LED or solar cells), the network performance can be optimized by employing a quasi-fractal structure of the network. We also consider the periodic metallic networks, where active plasmonic refraction leads to the phenomenon of the extraordinary optical transmission. We review the relevant literature on this topic, and demonstrate networks, which take advantage of this strategy (the bio-inspired leaf venation (LV) network, hybrid networks, etc.). Finally, we review “smart” TCs, with an added functionality, such as light interference, metamaterial effects, built-in semiconductors, and their junctions.","PeriodicalId":7373,"journal":{"name":"Advances in Physics","volume":"48 1","pages":"553 - 617"},"PeriodicalIF":0.0,"publicationDate":"2016-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/00018732.2016.1226804","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58773345","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}