Pontus Laurell, Bradraj Pandey, Gábor B. Halász, Satoshi Okamoto, Gonzalo Alvarez, Elbio Dagotto
We study the impact of hole-doping on the Kitaev-Heisenberg model on the honeycomb lattice. We investigate the pairing tendencies and correlation functions in the framework of a $t-J-K$ model using density matrix renormalization group calculations on three-leg cylinders. In the case of the pure Kitaev model, which realizes a quantum spin-liquid phase at half-filling, we find that binding of two holes only occurs at low values of the hopping, where the holes are slow. We have theoretically verified that pair formation occurs in the limit of immobile holes, where the pure Kitaev model remains exactly solvable. When we instead fix the hopping at an intermediate, more realistic, value, and vary the Heisenberg and Kitaev interaction strengths, we find pairing tendencies only in the N'eel phase. This is in contrast to prior mean-field calculations, highlighting the importance of accounting for the kinetic energy of dopants in generalized Kitaev models. Interestingly, we also find signatures of pair-density wave formation over the studied range of model parameters, namely a periodic modulation of the charge density as well as the spin-spin and pair-pair correlations in real space. Moreover, we present a comparative study of the different correlations as a function of doping. We finally discuss the potential for experimentally observing the studied physics in quantum materials and heterostructures.
{"title":"Pairing tendencies in the doped Kitaev-Heisenberg model","authors":"Pontus Laurell, Bradraj Pandey, Gábor B. Halász, Satoshi Okamoto, Gonzalo Alvarez, Elbio Dagotto","doi":"arxiv-2409.04389","DOIUrl":"https://doi.org/arxiv-2409.04389","url":null,"abstract":"We study the impact of hole-doping on the Kitaev-Heisenberg model on the\u0000honeycomb lattice. We investigate the pairing tendencies and correlation\u0000functions in the framework of a $t-J-K$ model using density matrix\u0000renormalization group calculations on three-leg cylinders. In the case of the\u0000pure Kitaev model, which realizes a quantum spin-liquid phase at half-filling,\u0000we find that binding of two holes only occurs at low values of the hopping,\u0000where the holes are slow. We have theoretically verified that pair formation\u0000occurs in the limit of immobile holes, where the pure Kitaev model remains\u0000exactly solvable. When we instead fix the hopping at an intermediate, more\u0000realistic, value, and vary the Heisenberg and Kitaev interaction strengths, we\u0000find pairing tendencies only in the N'eel phase. This is in contrast to prior\u0000mean-field calculations, highlighting the importance of accounting for the\u0000kinetic energy of dopants in generalized Kitaev models. Interestingly, we also\u0000find signatures of pair-density wave formation over the studied range of model\u0000parameters, namely a periodic modulation of the charge density as well as the\u0000spin-spin and pair-pair correlations in real space. Moreover, we present a\u0000comparative study of the different correlations as a function of doping. We\u0000finally discuss the potential for experimentally observing the studied physics\u0000in quantum materials and heterostructures.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210231","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}
S. J. Li, D. Zhao, J. Li, B. L. Kang, M. Shan, Y. B. Zhou, X. Y. Li, T. Wu, X. H. Chen
Exchange bias (EB) is a fundamental phenomenon in widespread information technologies. However, a comprehensive understanding of its microscopic origin remains a great challenge. One key issue in the debate is the role of frustration and disorder in the EB mechanism, which motivates the exploration of the EB effect in spin glass (SG) systems. Here,in the SG state of Cr-doped Hund's metal CsFe2As2, we discover a giant EB effect with a maximum bias field of ~ 2 Tesla, which is almost two orders of magnitude larger than that of traditional alloy SGs. Our results indicate that the giant EB effect should originate from the exchange interactions at the natural boundaries between the tunable ferromagnetic-like (FM) regions around Cr dopants and the SG matrix, via which the FM spins are strongly pinned by the frozen spins in the SG matrix. In addition, the temperature-dependent and cooling-field-dependent EB behaviors could be interpreted well by the SG model with frustrated FM/SG boundaries, which provides an intuitive and explicit understanding of the impact of glassy parameters on the EB effect. All these results suggest that the correlated metals are promising directions for exploring the EB effect in the SG state.
{"title":"Spin freezing induced giant exchange bias in a doped Hund's metal","authors":"S. J. Li, D. Zhao, J. Li, B. L. Kang, M. Shan, Y. B. Zhou, X. Y. Li, T. Wu, X. H. Chen","doi":"arxiv-2409.04149","DOIUrl":"https://doi.org/arxiv-2409.04149","url":null,"abstract":"Exchange bias (EB) is a fundamental phenomenon in widespread information\u0000technologies. However, a comprehensive understanding of its microscopic origin\u0000remains a great challenge. One key issue in the debate is the role of\u0000frustration and disorder in the EB mechanism, which motivates the exploration\u0000of the EB effect in spin glass (SG) systems. Here,in the SG state of Cr-doped\u0000Hund's metal CsFe2As2, we discover a giant EB effect with a maximum bias field\u0000of ~ 2 Tesla, which is almost two orders of magnitude larger than that of\u0000traditional alloy SGs. Our results indicate that the giant EB effect should\u0000originate from the exchange interactions at the natural boundaries between the\u0000tunable ferromagnetic-like (FM) regions around Cr dopants and the SG matrix,\u0000via which the FM spins are strongly pinned by the frozen spins in the SG\u0000matrix. In addition, the temperature-dependent and cooling-field-dependent EB\u0000behaviors could be interpreted well by the SG model with frustrated FM/SG\u0000boundaries, which provides an intuitive and explicit understanding of the\u0000impact of glassy parameters on the EB effect. All these results suggest that\u0000the correlated metals are promising directions for exploring the EB effect in\u0000the SG state.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210192","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}
The recent suggestion of valence-skipping phenomenon driving a two-gap superconductivity in $Ag$-doped SnSe, by Kataria, textit{et al.} [Phys. Rev. B 107, 174517 (2023)], has brought to the fore a long-standing issue once again. The absence of crystallographically inequivalent Sn cites corroborated by electronic properties of AgSnSe$_2$, calculated using first-principles density functional theory, however, does not appear to provide a strong support in favor of valence-skipping in this system. Interestingly, the signature of avoided band-crossings (with the inclusion of SOC) and non-zero textit{mirror} Chern number ($n_{mathcal{M}}$) confirm a non-trivial topology. The presence of mirror symmetry-protected surface states along the mirror planes indicates that AgSnSe$_2$ could be a potential candidate for topological crystalline insulators (TCIs). Moreover, our calculation of electron-phonon coupling and anisotropic superconducting properties of AgSnSe$_2$, using Migdal-Eliashberg theory, gives a single-gap superconductivity with critical temperature $T_c approx 7$K, consistent with the experimental value of $5$K. The interplay of topology and superconductivity in this three-dimensional material appears quite intriguing and it may provide new insights into the exploration of superconductivity and topology.
{"title":"Superconductivity, topological crystalline insulator and the absence of valence-skipping in AgSnSe$_2$","authors":"Shubham Patel, A Taraphder","doi":"arxiv-2409.04096","DOIUrl":"https://doi.org/arxiv-2409.04096","url":null,"abstract":"The recent suggestion of valence-skipping phenomenon driving a two-gap\u0000superconductivity in $Ag$-doped SnSe, by Kataria, textit{et al.} [Phys. Rev. B\u0000107, 174517 (2023)], has brought to the fore a long-standing issue once again.\u0000The absence of crystallographically inequivalent Sn cites corroborated by\u0000electronic properties of AgSnSe$_2$, calculated using first-principles density\u0000functional theory, however, does not appear to provide a strong support in\u0000favor of valence-skipping in this system. Interestingly, the signature of\u0000avoided band-crossings (with the inclusion of SOC) and non-zero textit{mirror}\u0000Chern number ($n_{mathcal{M}}$) confirm a non-trivial topology. The presence\u0000of mirror symmetry-protected surface states along the mirror planes indicates\u0000that AgSnSe$_2$ could be a potential candidate for topological crystalline\u0000insulators (TCIs). Moreover, our calculation of electron-phonon coupling and\u0000anisotropic superconducting properties of AgSnSe$_2$, using Migdal-Eliashberg\u0000theory, gives a single-gap superconductivity with critical temperature $T_c\u0000approx 7$K, consistent with the experimental value of $5$K. The interplay of\u0000topology and superconductivity in this three-dimensional material appears quite\u0000intriguing and it may provide new insights into the exploration of\u0000superconductivity and topology.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210187","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}
Anastasiya Lebedeva, Matúš Hladký, Marcel Polák, František Herman
Nowadays superconducting radio frequency (SRF) cavities represent fundamental tools used for (Standard Model) particle acceleration, (beyond Standard Model) particle probing and long-lifetime photon preservation. We study the SRF frequency shift in the vicinity of the critical temperature $T_c$ and the quality factor mainly at low temperatures within the Dynes superconductor model. We scrutinize and use the local limit response to the external electromagnetic field. Our approach allows for a finer analysis of the peculiar behavior of the resonant frequency shift immensely close to $T_c$, observed in recent experiments. In the ideal dirty limit, we analytically elaborate on the width and depth of the resulting dip. Studying the sign of the slope of the resonant frequency shift at $T_c$ in the moderately clean regime reveals the role of the pair-breaking and pair-conserving disorder. Next, to find the relevance of our description, we compare and also fit our results with the recent experimental data from the N-doped Nb sample presented in [arXiv:2307.07905v1]. Our analysis remarkably complies with the experimental findings, especially concerning the dip width. We offer straightforward, homogeneous-disorder-based interpretation within the moderately clean regime. Assuming the same regime at low temperatures, we address details of the high-quality plateaus. Summing all up, this work presents (and studies the limits of) the simple effective description of the complex problem corresponding to the electromagnetic response in the superconductors combining homogeneous conventional pairing and two different kinds of disorder scattering.
{"title":"Local Limit Disorder Characteristics of Superconducting Radio Frequency Cavities","authors":"Anastasiya Lebedeva, Matúš Hladký, Marcel Polák, František Herman","doi":"arxiv-2409.04203","DOIUrl":"https://doi.org/arxiv-2409.04203","url":null,"abstract":"Nowadays superconducting radio frequency (SRF) cavities represent fundamental\u0000tools used for (Standard Model) particle acceleration, (beyond Standard Model)\u0000particle probing and long-lifetime photon preservation. We study the SRF\u0000frequency shift in the vicinity of the critical temperature $T_c$ and the\u0000quality factor mainly at low temperatures within the Dynes superconductor\u0000model. We scrutinize and use the local limit response to the external\u0000electromagnetic field. Our approach allows for a finer analysis of the peculiar\u0000behavior of the resonant frequency shift immensely close to $T_c$, observed in\u0000recent experiments. In the ideal dirty limit, we analytically elaborate on the\u0000width and depth of the resulting dip. Studying the sign of the slope of the\u0000resonant frequency shift at $T_c$ in the moderately clean regime reveals the\u0000role of the pair-breaking and pair-conserving disorder. Next, to find the\u0000relevance of our description, we compare and also fit our results with the\u0000recent experimental data from the N-doped Nb sample presented in\u0000[arXiv:2307.07905v1]. Our analysis remarkably complies with the experimental\u0000findings, especially concerning the dip width. We offer straightforward,\u0000homogeneous-disorder-based interpretation within the moderately clean regime.\u0000Assuming the same regime at low temperatures, we address details of the\u0000high-quality plateaus. Summing all up, this work presents (and studies the\u0000limits of) the simple effective description of the complex problem\u0000corresponding to the electromagnetic response in the superconductors combining\u0000homogeneous conventional pairing and two different kinds of disorder\u0000scattering.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210185","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}
The exploration of superconductors in metastable phases by manipulating crystal structures through high-pressure techniques has attracted significant interest in materials science to achieve a high critical temperature ($T_c$). In this study, we report an emergence of novel superconductivity in a metastable phase of Th$_3$P$_4$-type cubic In$_{3-x}$S$_4$ with remarkably high $T_c$ at 20 K under 45 GPa by using an originally designed diamond anvil cell equipped with boron-doped diamond electrodes, which can perform a high-pressure synthesis and an in-situ electrical transport measurement simultaneously. In-situ structural analysis indicates that the In$_{3-x}$S$_4$ appears partially above 40 GPa without heating. The high-pressure annealing treatment induces complete transformation to the Th$_3$P$_4$-type structure, and the defected concentration of x in In$_{3-x}$S$_4$ decreases with increasing annealing temperature. The $T_c$ in In$_{3-x}$S$_4$ is maximized at x = 0 and approaches 20 K. Electronic band calculations show that the high density of states composed of sulfur and indium bands are located at the conduction band bottom near Fermi energy. The record high $T_c$ in In$_{3-x}$S$_4$ among superconducting sulfides accelerates the further exploration of high $T_c$ materials within the Th$_3$P$_4$-type cubic family by using flexibility in crystal structure.
{"title":"Emergence of Superconductivity at 20 K in Th$_3$P$_4$-type In$_{3-x}$S$_4$ Synthesized by Diamond Anvil Cell with Boron-doped Diamond Electrodes","authors":"Ryo Matsumoto, Kazuki Yamane, Terumasa Tadano, Kensei Terashima, Toru Shinmei, Tetsuo Irifune, Yoshihiko Takano","doi":"arxiv-2409.03409","DOIUrl":"https://doi.org/arxiv-2409.03409","url":null,"abstract":"The exploration of superconductors in metastable phases by manipulating\u0000crystal structures through high-pressure techniques has attracted significant\u0000interest in materials science to achieve a high critical temperature ($T_c$).\u0000In this study, we report an emergence of novel superconductivity in a\u0000metastable phase of Th$_3$P$_4$-type cubic In$_{3-x}$S$_4$ with remarkably high\u0000$T_c$ at 20 K under 45 GPa by using an originally designed diamond anvil cell\u0000equipped with boron-doped diamond electrodes, which can perform a high-pressure\u0000synthesis and an in-situ electrical transport measurement simultaneously.\u0000In-situ structural analysis indicates that the In$_{3-x}$S$_4$ appears\u0000partially above 40 GPa without heating. The high-pressure annealing treatment\u0000induces complete transformation to the Th$_3$P$_4$-type structure, and the\u0000defected concentration of x in In$_{3-x}$S$_4$ decreases with increasing\u0000annealing temperature. The $T_c$ in In$_{3-x}$S$_4$ is maximized at x = 0 and\u0000approaches 20 K. Electronic band calculations show that the high density of\u0000states composed of sulfur and indium bands are located at the conduction band\u0000bottom near Fermi energy. The record high $T_c$ in In$_{3-x}$S$_4$ among\u0000superconducting sulfides accelerates the further exploration of high $T_c$\u0000materials within the Th$_3$P$_4$-type cubic family by using flexibility in\u0000crystal structure.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210232","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}
Multidimensional spectroscopy has a long history originating from nuclear magnetic resonance, and has now found widespread application at infrared and optical frequencies as well. However, the energy scales of traditional multidimensional probes have been ill-suited for studying quantum materials. Recent technological advancements have now enabled extension of these multidimensional techniques to the terahertz frequency range, in which collective excitations of quantum materials are typically found. This Perspective introduces the technique of two-dimensional terahertz spectroscopy (2DTS) and the unique physics of quantum materials revealed by 2DTS spectra, accompanied by a selection of the rapidly expanding experimental and theoretical literature. While 2DTS has so far been primarily applied to quantum materials at equilibrium, we provide an outlook for its application towards understanding their dynamical non-equilibrium states and beyond.
{"title":"Multidimensional Terahertz Probes of Quantum Materials","authors":"Albert Liu","doi":"arxiv-2409.03719","DOIUrl":"https://doi.org/arxiv-2409.03719","url":null,"abstract":"Multidimensional spectroscopy has a long history originating from nuclear\u0000magnetic resonance, and has now found widespread application at infrared and\u0000optical frequencies as well. However, the energy scales of traditional\u0000multidimensional probes have been ill-suited for studying quantum materials.\u0000Recent technological advancements have now enabled extension of these\u0000multidimensional techniques to the terahertz frequency range, in which\u0000collective excitations of quantum materials are typically found. This\u0000Perspective introduces the technique of two-dimensional terahertz spectroscopy\u0000(2DTS) and the unique physics of quantum materials revealed by 2DTS spectra,\u0000accompanied by a selection of the rapidly expanding experimental and\u0000theoretical literature. While 2DTS has so far been primarily applied to quantum\u0000materials at equilibrium, we provide an outlook for its application towards\u0000understanding their dynamical non-equilibrium states and beyond.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210236","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}
Shuyuan Huyan, Nestor Haberkorn, Mingyu Xu, Paul C. Canfield, Sergey L. Bud'ko
Measurements of low field magnetization, trapped flux magnetization and 5 K flux creep in single crystal of CaKFe$_4$As$_4$ under pressure up to 7.5 GPa in a diamond pressure cell are presented. The observed evolution of the temperature dependence of the self-field critical current and slowing down of the base temperature flux creep rate are explained within the two sources of pinning hypothesis involving presence of CaKFe$_4$As$_4$ intergrowths suggested in the literature. Above the half collapsed tetragonal structural transition under pressure, where superconductivity is non-bulk or absent, critically diminished or no diamagnetism and flux trapped magnetization were observed.
{"title":"Competition between the modification of intrinsic superconducting properties and the pinning landscape under external pressure in CaKFe$_4$As$_4$ single crystals","authors":"Shuyuan Huyan, Nestor Haberkorn, Mingyu Xu, Paul C. Canfield, Sergey L. Bud'ko","doi":"arxiv-2409.03809","DOIUrl":"https://doi.org/arxiv-2409.03809","url":null,"abstract":"Measurements of low field magnetization, trapped flux magnetization and 5 K\u0000flux creep in single crystal of CaKFe$_4$As$_4$ under pressure up to 7.5 GPa in\u0000a diamond pressure cell are presented. The observed evolution of the\u0000temperature dependence of the self-field critical current and slowing down of\u0000the base temperature flux creep rate are explained within the two sources of\u0000pinning hypothesis involving presence of CaKFe$_4$As$_4$ intergrowths suggested\u0000in the literature. Above the half collapsed tetragonal structural transition\u0000under pressure, where superconductivity is non-bulk or absent, critically\u0000diminished or no diamagnetism and flux trapped magnetization were observed.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210190","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}
N. K Gupta, R. Gong, Y. Wu, M. Kang, C. T. Parzyck, B. Z. Gregory, N. Costa, R. Sutarto, S. Sarker, A. Singer, D. G. Schlom, K. M. Shen, D. G. Hawthorn
The discovery of superconductivity in La$_3$Ni$_2$O$_7$ under pressure has motivated the investigation of a parent spin density wave (SDW) state which could provide the underlying pairing interaction. Here, we employ resonant soft x-ray scattering and polarimetry on thin films of bilayer La$_3$Ni$_2$O$_7$ to determine that the magnetic structure of the SDW forms unidirectional diagonal spin stripes with moments lying within the NiO$_2$ plane and perpendicular to $mathbf{Q}_{SDW}$, but without the strong charge disproportionation typically associated with other nickelates. These stripes form anisotropic domains with shorter correlation lengths perpendicular versus parallel to $mathbf{Q}_{SDW}$, revealing nanoscale rotational and translational symmetry breaking analogous to the cuprate and Fe-based superconductors, with Bloch-like antiferromagnetic domain walls separating orthogonal domains.
{"title":"Anisotropic Spin Stripe Domains in Bilayer La$_3$Ni$_2$O$_7$","authors":"N. K Gupta, R. Gong, Y. Wu, M. Kang, C. T. Parzyck, B. Z. Gregory, N. Costa, R. Sutarto, S. Sarker, A. Singer, D. G. Schlom, K. M. Shen, D. G. Hawthorn","doi":"arxiv-2409.03210","DOIUrl":"https://doi.org/arxiv-2409.03210","url":null,"abstract":"The discovery of superconductivity in La$_3$Ni$_2$O$_7$ under pressure has\u0000motivated the investigation of a parent spin density wave (SDW) state which\u0000could provide the underlying pairing interaction. Here, we employ resonant soft\u0000x-ray scattering and polarimetry on thin films of bilayer La$_3$Ni$_2$O$_7$ to\u0000determine that the magnetic structure of the SDW forms unidirectional diagonal\u0000spin stripes with moments lying within the NiO$_2$ plane and perpendicular to\u0000$mathbf{Q}_{SDW}$, but without the strong charge disproportionation typically\u0000associated with other nickelates. These stripes form anisotropic domains with\u0000shorter correlation lengths perpendicular versus parallel to\u0000$mathbf{Q}_{SDW}$, revealing nanoscale rotational and translational symmetry\u0000breaking analogous to the cuprate and Fe-based superconductors, with Bloch-like\u0000antiferromagnetic domain walls separating orthogonal domains.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"259 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210234","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}
P. K. Meena, S. Jangid, R. K. Kushwaha, P. Manna, S. Sharma, P. Mishra, R. P. Singh
Transition-metal-based carbides (TMCs), renowned for their exceptional hardness, mechanical strength, and thermal properties, have recently emerged as promising candidates for topological superconductivity. In this study, we synthesized ReC in the NaCl structure at ambient pressure by substituting Mo or W at the Re-site. We investigated the superconducting properties of Re$_{1-x}$T$_{x}$C (where T = Mo, W) for $x = 0.5$ using magnetization, resistivity and specific heat measurements. These compounds display type-II, fully gapped, weakly coupled superconductivity with high critical fields, establishing them as new members of superconducting ultra-hard materials at ambient pressure and paving the way for superconducting device applications under extreme conditions.
过渡金属基碳化物（TMC）以其优异的硬度、机械强度和热性能而闻名，最近已成为拓扑超导性的理想候选材料。在这项研究中，我们通过在 Re-site 处取代 Mo 或 W，在常压下在 NaCl 结构中合成了 ReC。我们利用磁化、电阻率和比热测量方法研究了 Re$_{1-x}$T$_{x}$C（其中 T = Mo、W）在 $x = 0.5$ 时的超导特性。这些化合物显示出具有高临界场的 II 型、全间隙、弱耦合超导性，使它们成为常压超导超硬材料的新成员，并为极端条件下的超导设备应用铺平了道路。
{"title":"Stabilization of Ambient Pressure Rocksalt Crystal Structure and High Critical Field Superconductivity in ReC via Mo and W Substitution","authors":"P. K. Meena, S. Jangid, R. K. Kushwaha, P. Manna, S. Sharma, P. Mishra, R. P. Singh","doi":"arxiv-2409.03592","DOIUrl":"https://doi.org/arxiv-2409.03592","url":null,"abstract":"Transition-metal-based carbides (TMCs), renowned for their exceptional\u0000hardness, mechanical strength, and thermal properties, have recently emerged as\u0000promising candidates for topological superconductivity. In this study, we\u0000synthesized ReC in the NaCl structure at ambient pressure by substituting Mo or\u0000W at the Re-site. We investigated the superconducting properties of\u0000Re$_{1-x}$T$_{x}$C (where T = Mo, W) for $x = 0.5$ using magnetization,\u0000resistivity and specific heat measurements. These compounds display type-II,\u0000fully gapped, weakly coupled superconductivity with high critical fields,\u0000establishing them as new members of superconducting ultra-hard materials at\u0000ambient pressure and paving the way for superconducting device applications\u0000under extreme conditions.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210230","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}
C. Cirillo, M. Ejrnaes, P. Ercolano, C. Bruscino, A. Cassinese, D. Salvoni, C. Attanasio, G. P. Pepe, L. Parlato
Superconducting Microstrip Single Photon Detectors (SMSPDs) are increasingly attracting the interest of the scientific community as a new platform for large area detectors with unprecedented advantaged in terms of fabrication. However, while their operativity at the telecommunication wavelength was achieved, working beyond 1.55 um is challenging. Here, we experimentally demonstrate single-photon operation of NbRe microstrips at wavelengths of 1.55 and 2 um. The devices are structured as pairs of parallel microstrips with widths ranging from 1.4 to 2.2 um and lengths from 5 to 10 um. This innovative design may assure large sensitive areas, without affecting the kinetic inductance, namely the time performance of the detectors. The results are discussed in the framework of the hot-spot two-temperature model.
{"title":"Single photon detection up to 2 um in pair of parallel microstrips based on NbRe ultrathin films","authors":"C. Cirillo, M. Ejrnaes, P. Ercolano, C. Bruscino, A. Cassinese, D. Salvoni, C. Attanasio, G. P. Pepe, L. Parlato","doi":"arxiv-2409.02619","DOIUrl":"https://doi.org/arxiv-2409.02619","url":null,"abstract":"Superconducting Microstrip Single Photon Detectors (SMSPDs) are increasingly\u0000attracting the interest of the scientific community as a new platform for large\u0000area detectors with unprecedented advantaged in terms of fabrication. However,\u0000while their operativity at the telecommunication wavelength was achieved,\u0000working beyond 1.55 um is challenging. Here, we experimentally demonstrate\u0000single-photon operation of NbRe microstrips at wavelengths of 1.55 and 2 um.\u0000The devices are structured as pairs of parallel microstrips with widths ranging\u0000from 1.4 to 2.2 um and lengths from 5 to 10 um. This innovative design may\u0000assure large sensitive areas, without affecting the kinetic inductance, namely\u0000the time performance of the detectors. The results are discussed in the\u0000framework of the hot-spot two-temperature model.","PeriodicalId":501069,"journal":{"name":"arXiv - PHYS - Superconductivity","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142210238","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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