Hole-doped high-temperature copper oxide-based superconductors (cuprates) exhibit complex phase diagrams where electronic orders like a charge density wave (CDW) and superconductivity (SC) appear at low temperatures. The origins of these electronic orders are still open questions due to their complex interplay and correlated nature. These electronic orders can modify the phonons in the system, which has also been experimentally found in several cuprates as a softening in the phonon frequency at the CDW vector. Recent experiments have revealed that the softening in phonons in cuprates due to CDW shows intriguing behavior with increasing hole doping. Hole doping can also change the underlying Fermi surface. Therefore, it is an interesting question whether the doping-induced change in the Fermi surface can affect the softening of phonons, which in turn can reveal the nature of the electronic orders present in the system. In this work, we investigate this question by studying the softening of phonons in the presence of CDW and SC within a perturbative approach developed in an earlier work. We compare the results obtained within the working model to some experiments.
{"title":"A Theoretical Study of Doping Evolution of Phonons in High-Temperature Cuprate Superconductors","authors":"Saheli Sarkar","doi":"10.3390/condmat9010013","DOIUrl":"https://doi.org/10.3390/condmat9010013","url":null,"abstract":"Hole-doped high-temperature copper oxide-based superconductors (cuprates) exhibit complex phase diagrams where electronic orders like a charge density wave (CDW) and superconductivity (SC) appear at low temperatures. The origins of these electronic orders are still open questions due to their complex interplay and correlated nature. These electronic orders can modify the phonons in the system, which has also been experimentally found in several cuprates as a softening in the phonon frequency at the CDW vector. Recent experiments have revealed that the softening in phonons in cuprates due to CDW shows intriguing behavior with increasing hole doping. Hole doping can also change the underlying Fermi surface. Therefore, it is an interesting question whether the doping-induced change in the Fermi surface can affect the softening of phonons, which in turn can reveal the nature of the electronic orders present in the system. In this work, we investigate this question by studying the softening of phonons in the presence of CDW and SC within a perturbative approach developed in an earlier work. We compare the results obtained within the working model to some experiments.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":"16 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139865348","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}
Hole-doped high-temperature copper oxide-based superconductors (cuprates) exhibit complex phase diagrams where electronic orders like a charge density wave (CDW) and superconductivity (SC) appear at low temperatures. The origins of these electronic orders are still open questions due to their complex interplay and correlated nature. These electronic orders can modify the phonons in the system, which has also been experimentally found in several cuprates as a softening in the phonon frequency at the CDW vector. Recent experiments have revealed that the softening in phonons in cuprates due to CDW shows intriguing behavior with increasing hole doping. Hole doping can also change the underlying Fermi surface. Therefore, it is an interesting question whether the doping-induced change in the Fermi surface can affect the softening of phonons, which in turn can reveal the nature of the electronic orders present in the system. In this work, we investigate this question by studying the softening of phonons in the presence of CDW and SC within a perturbative approach developed in an earlier work. We compare the results obtained within the working model to some experiments.
{"title":"A Theoretical Study of Doping Evolution of Phonons in High-Temperature Cuprate Superconductors","authors":"Saheli Sarkar","doi":"10.3390/condmat9010013","DOIUrl":"https://doi.org/10.3390/condmat9010013","url":null,"abstract":"Hole-doped high-temperature copper oxide-based superconductors (cuprates) exhibit complex phase diagrams where electronic orders like a charge density wave (CDW) and superconductivity (SC) appear at low temperatures. The origins of these electronic orders are still open questions due to their complex interplay and correlated nature. These electronic orders can modify the phonons in the system, which has also been experimentally found in several cuprates as a softening in the phonon frequency at the CDW vector. Recent experiments have revealed that the softening in phonons in cuprates due to CDW shows intriguing behavior with increasing hole doping. Hole doping can also change the underlying Fermi surface. Therefore, it is an interesting question whether the doping-induced change in the Fermi surface can affect the softening of phonons, which in turn can reveal the nature of the electronic orders present in the system. In this work, we investigate this question by studying the softening of phonons in the presence of CDW and SC within a perturbative approach developed in an earlier work. We compare the results obtained within the working model to some experiments.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139805458","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}
Liquids and gases are distinct in their extent of dynamic atomic correlations; in gases, atoms are almost uncorrelated, whereas they are strongly correlated in liquids. This distinction applies also to electronic systems. Fermi liquids are actually gas-like, whereas strongly correlated electrons are liquid-like. Doped Mott insulators share characteristics with supercooled liquids. Such distinctions have important implications for superconductivity. We discuss the nature of dynamic atomic correlations in liquids and a possible effect of strong electron correlations and Bose–Einstein condensation on the high-temperature superconductivity of the cuprates.
{"title":"Dynamic Correlations in Disordered Systems: Implications for High-Temperature Superconductivity","authors":"Takeshi Egami","doi":"10.3390/condmat9010012","DOIUrl":"https://doi.org/10.3390/condmat9010012","url":null,"abstract":"Liquids and gases are distinct in their extent of dynamic atomic correlations; in gases, atoms are almost uncorrelated, whereas they are strongly correlated in liquids. This distinction applies also to electronic systems. Fermi liquids are actually gas-like, whereas strongly correlated electrons are liquid-like. Doped Mott insulators share characteristics with supercooled liquids. Such distinctions have important implications for superconductivity. We discuss the nature of dynamic atomic correlations in liquids and a possible effect of strong electron correlations and Bose–Einstein condensation on the high-temperature superconductivity of the cuprates.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":"34 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139867547","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}
Liquids and gases are distinct in their extent of dynamic atomic correlations; in gases, atoms are almost uncorrelated, whereas they are strongly correlated in liquids. This distinction applies also to electronic systems. Fermi liquids are actually gas-like, whereas strongly correlated electrons are liquid-like. Doped Mott insulators share characteristics with supercooled liquids. Such distinctions have important implications for superconductivity. We discuss the nature of dynamic atomic correlations in liquids and a possible effect of strong electron correlations and Bose–Einstein condensation on the high-temperature superconductivity of the cuprates.
{"title":"Dynamic Correlations in Disordered Systems: Implications for High-Temperature Superconductivity","authors":"Takeshi Egami","doi":"10.3390/condmat9010012","DOIUrl":"https://doi.org/10.3390/condmat9010012","url":null,"abstract":"Liquids and gases are distinct in their extent of dynamic atomic correlations; in gases, atoms are almost uncorrelated, whereas they are strongly correlated in liquids. This distinction applies also to electronic systems. Fermi liquids are actually gas-like, whereas strongly correlated electrons are liquid-like. Doped Mott insulators share characteristics with supercooled liquids. Such distinctions have important implications for superconductivity. We discuss the nature of dynamic atomic correlations in liquids and a possible effect of strong electron correlations and Bose–Einstein condensation on the high-temperature superconductivity of the cuprates.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":"215 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139808024","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}
In order to search for possible residual minor phases in the Y-Ba-Cu-O family, powdered mixtures of Y2O3 + BaCO3 + CuO and, independently, superconducting compound YBa2Cu3O7−x have been treated in evacuated cells and elevated temperatures. YBa2Cu3O7−x was reduced to YBa2Cu3O5 by use of the special home-designed Taconis–Knudsen vacuum device. Subsequent doping by oxygen converts produced insulator YBa2Cu3O5 to semiconductor or metal YBa2Cu3O5+x (0 < x < 0.3). In addition to YBa2Cu3O5, 0.05 volume percent of the minor delafossite phase Y2Cu2O4 was spotted in the powder mixture 1/2 Y2O3 + 2BaCO3 + 6Cu2O, heated up to 818 °C in an inert gas atmosphere. An attempt to prepare the insulating bulk delafossite samples was successful, and subsequent doping by oxygen produced novel metallic phases.
{"title":"Search for Novel Phases in Y-Ba-Cu-O Family","authors":"Danijel Djurek","doi":"10.3390/condmat9010010","DOIUrl":"https://doi.org/10.3390/condmat9010010","url":null,"abstract":"In order to search for possible residual minor phases in the Y-Ba-Cu-O family, powdered mixtures of Y2O3 + BaCO3 + CuO and, independently, superconducting compound YBa2Cu3O7−x have been treated in evacuated cells and elevated temperatures. YBa2Cu3O7−x was reduced to YBa2Cu3O5 by use of the special home-designed Taconis–Knudsen vacuum device. Subsequent doping by oxygen converts produced insulator YBa2Cu3O5 to semiconductor or metal YBa2Cu3O5+x (0 < x < 0.3). In addition to YBa2Cu3O5, 0.05 volume percent of the minor delafossite phase Y2Cu2O4 was spotted in the powder mixture 1/2 Y2O3 + 2BaCO3 + 6Cu2O, heated up to 818 °C in an inert gas atmosphere. An attempt to prepare the insulating bulk delafossite samples was successful, and subsequent doping by oxygen produced novel metallic phases.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":" 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139616937","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}
V. Neverov, A. Lukyanov, A. Krasavin, Alexei Vagov, Mihail D. Croitoru
The pursuit of enhanced superconducting device performance has historically focused on minimizing disorder in materials. Recent research, however, challenges this conventional wisdom by exploring the unique characteristics of disordered materials. Following the studies, disorder is currently viewed as a design parameter that can be tuned. This shift in the paradigm has sparked an upsurge in research efforts, which demonstrates that disorder can significantly augment the superconductivity figures of merit. While almost all previous studies attended to the effects related to disorder strength, this article focuses on the impact of short-range disorder correlations that in real materials takes place, for example, due to lattice defects. The study shows that the degree of such correlations can strongly influence the superconducting characteristics.
{"title":"The Impact of Short-Range (Gaussian) Disorder Correlations on Superconducting Characteristics","authors":"V. Neverov, A. Lukyanov, A. Krasavin, Alexei Vagov, Mihail D. Croitoru","doi":"10.3390/condmat9010006","DOIUrl":"https://doi.org/10.3390/condmat9010006","url":null,"abstract":"The pursuit of enhanced superconducting device performance has historically focused on minimizing disorder in materials. Recent research, however, challenges this conventional wisdom by exploring the unique characteristics of disordered materials. Following the studies, disorder is currently viewed as a design parameter that can be tuned. This shift in the paradigm has sparked an upsurge in research efforts, which demonstrates that disorder can significantly augment the superconductivity figures of merit. While almost all previous studies attended to the effects related to disorder strength, this article focuses on the impact of short-range disorder correlations that in real materials takes place, for example, due to lattice defects. The study shows that the degree of such correlations can strongly influence the superconducting characteristics.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":" 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139625140","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}
Eleni Konstantakopoulou, Annalaura Casanova Municchia, Loredana Luvidi, Marco Ferretti
Handheld X-ray Fluorescence devices (HH-XRF) have given archaeologists and conservators the opportunity to study a wide range of materials encountered in their work with great accessibility and flexibility. The investigation of copper-based artefacts is a frequent application of these instruments in the field of cultural heritage as it gives direct and rapid quantitative results that can provide very important information about them, such as their fabrication technology. This paper discusses the comparison of quantitative results, obtained by a commercial handheld XRF device “Bruker Tracer 5g” on certified standards, compositionally significant in copper-based alloys of interest in the field of cultural heritage. The measured elemental concentrations were derived using three different calibrations, which were examined for their accuracy. Two of them were based on the empirical coefficients approach, performed by the built-in calibration/software (copper alloy calibrations provided by Bruker manufacturer and the Bruker EasyCal software), while the third one was performed off-line by processing the spectra with an independent fundamental parameters (FP) software (PyMca version 5.9.2., a X-ray fluorescence analysis software developed at the European Synchrotron Radiation Facility). The results highlight that although HH-XRF devices simplify data collection, for optimal quantitative results, the correct choice of analysis conditions and calibration method still requires a detailed understanding of the principles of X-ray spectrometry.
手持式 X 射线荧光设备（HH-XRF）为考古学家和文物保护人员提供了研究工作中遇到的各种材料的机会，具有极大的便利性和灵活性。对铜制文物的调查是这些仪器在文化遗产领域的一个常见应用，因为它能提供直接、快速的定量结果，从而提供有关文物的重要信息，如其制造技术。本文讨论了商用手持式 XRF 设备 "Bruker Tracer 5g "在认证标准上获得的定量结果的比较，这些标准对文化遗产领域感兴趣的铜基合金具有重要的成分意义。测量的元素浓度是通过三种不同的定标得出的，并对其准确性进行了检验。其中两个定标是基于经验系数法，由内置定标/软件（布鲁克制造商提供的铜合金定标和布鲁克 EasyCal 软件）执行，而第三个定标是通过独立的基本参数 (FP) 软件（PyMca 5.9.2 版，欧洲同步辐射设施开发的 X 射线荧光分析软件）离线处理光谱。结果表明，尽管 HH-XRF 设备简化了数据采集，但要获得最佳定量结果，正确选择分析条件和校准方法仍然需要详细了解 X 射线光谱分析原理。
{"title":"Comparison of Different Methods for Evaluating Quantitative X-ray Fluorescence Data in Copper-Based Artefacts","authors":"Eleni Konstantakopoulou, Annalaura Casanova Municchia, Loredana Luvidi, Marco Ferretti","doi":"10.3390/condmat9010005","DOIUrl":"https://doi.org/10.3390/condmat9010005","url":null,"abstract":"Handheld X-ray Fluorescence devices (HH-XRF) have given archaeologists and conservators the opportunity to study a wide range of materials encountered in their work with great accessibility and flexibility. The investigation of copper-based artefacts is a frequent application of these instruments in the field of cultural heritage as it gives direct and rapid quantitative results that can provide very important information about them, such as their fabrication technology. This paper discusses the comparison of quantitative results, obtained by a commercial handheld XRF device “Bruker Tracer 5g” on certified standards, compositionally significant in copper-based alloys of interest in the field of cultural heritage. The measured elemental concentrations were derived using three different calibrations, which were examined for their accuracy. Two of them were based on the empirical coefficients approach, performed by the built-in calibration/software (copper alloy calibrations provided by Bruker manufacturer and the Bruker EasyCal software), while the third one was performed off-line by processing the spectra with an independent fundamental parameters (FP) software (PyMca version 5.9.2., a X-ray fluorescence analysis software developed at the European Synchrotron Radiation Facility). The results highlight that although HH-XRF devices simplify data collection, for optimal quantitative results, the correct choice of analysis conditions and calibration method still requires a detailed understanding of the principles of X-ray spectrometry.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":"9 47","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139437631","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}
Maurizio Chiti, Daniele Chiti, Federico Chiarelli, Raffaella Donghia, Adolfo Esposito, Marco Ferretti, A. Gorghinian
X-ray fluorescence (XRF) is a successful technique often used for the elemental analysis of cultural heritage artefacts. It is non-invasive, the equipment can be miniaturized and made portable and it allows addressing crucial issues such as the fabrication technology, authenticity and provenance of the artefacts. Depending on the components’ selection (e.g., the primary source, the detector and the focusing optics, if present), the analytical performance and the consequent suitability to investigate a given class of materials may vary significantly. The present paper discusses the analytical performance—with special regard to the limits of detection and the quantification uncertainty—of two portable XRF spectrometers developed within a collaboration between INFN-LNF-FISMEL and CNR-ISPC. The devices are expressly designed for heritage materials. In particular, one is equipped with focusing optics and it is intended to analyze small details on glasses and pigmented surfaces, whereas the other has a 70 kV X-ray tube, which greatly improves sensitivity for medium-Z elements, which is important in copper-based artefacts. Finally, this paper discusses two case studies to highlight the features of the instruments: one concerns Etruscan vitreous material beads and the other pre- and proto-historic copper-based artefacts from Tyrrhenian Central Italy. Thanks to the small size of the equipment, both investigations could easily be carried out in situ, namely, at the Museo Nazionale Etrusco in Rome and the Museo della Preistoria della Tuscia e della Rocca Farnese at Valentano.
X 射线荧光（XRF）是一项成功的技术，常用于文化遗产文物的元素分析。它是非侵入性的，设备可以小型化和便携化，并且可以解决文物的制造技术、真实性和来源等关键问题。根据组件选择的不同（如主光源、探测器和聚焦光学器件（如果有的话）），分析性能以及是否适合研究特定类别的材料可能会有很大差异。本文讨论了 INFN-LNF-FISMEL 和 CNR-ISPC 合作开发的两款便携式 XRF 光谱仪的分析性能，特别是检测极限和定量不确定性。这两台设备是专门为文物材料设计的。其中一个配备了聚焦光学镜片，用于分析玻璃和颜料表面的小细节，而另一个则配备了 70 kV X 射线管，大大提高了对中等 Z 元素的灵敏度，这对铜质文物非常重要。最后，本文讨论了两个案例研究，以突出仪器的特点：一个涉及伊特鲁里亚玻璃珠，另一个涉及意大利中部第勒尼安河流域的史前和史前铜器。由于设备体积小，这两项研究都可以很容易地在现场进行，即在罗马伊特鲁里亚国家博物馆和瓦伦塔诺的托斯卡纳和法尔内塞城堡史前博物馆。
{"title":"Design and Use of Portable X-ray Fluorescence Devices for the Analysis of Heritage Materials","authors":"Maurizio Chiti, Daniele Chiti, Federico Chiarelli, Raffaella Donghia, Adolfo Esposito, Marco Ferretti, A. Gorghinian","doi":"10.3390/condmat9010001","DOIUrl":"https://doi.org/10.3390/condmat9010001","url":null,"abstract":"X-ray fluorescence (XRF) is a successful technique often used for the elemental analysis of cultural heritage artefacts. It is non-invasive, the equipment can be miniaturized and made portable and it allows addressing crucial issues such as the fabrication technology, authenticity and provenance of the artefacts. Depending on the components’ selection (e.g., the primary source, the detector and the focusing optics, if present), the analytical performance and the consequent suitability to investigate a given class of materials may vary significantly. The present paper discusses the analytical performance—with special regard to the limits of detection and the quantification uncertainty—of two portable XRF spectrometers developed within a collaboration between INFN-LNF-FISMEL and CNR-ISPC. The devices are expressly designed for heritage materials. In particular, one is equipped with focusing optics and it is intended to analyze small details on glasses and pigmented surfaces, whereas the other has a 70 kV X-ray tube, which greatly improves sensitivity for medium-Z elements, which is important in copper-based artefacts. Finally, this paper discusses two case studies to highlight the features of the instruments: one concerns Etruscan vitreous material beads and the other pre- and proto-historic copper-based artefacts from Tyrrhenian Central Italy. Thanks to the small size of the equipment, both investigations could easily be carried out in situ, namely, at the Museo Nazionale Etrusco in Rome and the Museo della Preistoria della Tuscia e della Rocca Farnese at Valentano.","PeriodicalId":505256,"journal":{"name":"Condensed Matter","volume":"48 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139449602","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}
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