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Xie T, Liu C, Kajimoto R, Ikeuchi K, Li S, Luo H. Spin fluctuations in the 112-type iron-based superconductor Ca 0.82La 0.18Fe 0.96Ni 0.04As 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:474001. [PMID: 36137515 DOI: 10.1088/1361-648x/ac9441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
We report time-of-flight inelastic neutron scattering (INS) investigations on the spin fluctuation spectrum in the 112-type iron-based superconductor (FeSC) Ca0.82La0.18Fe0.96Ni0.04As2(CaLa-112). In comparison to the 122-type FeSCs with a centrosymmetric tetragonal lattice structure (space groupI4/mmm) at room temperature and an in-plane stripe-type antiferromagnetic (AF) order at low temperature, the 112 system has a noncentrosymmetric structure (space groupP21) with additional zigzag arsenic chains between Ca/La layers and a magnetic ground state with similar wavevectorQAFbut different orientations of ordered moments in the parent compounds. Our INS study clearly reveals that the in-plane dispersions and the bandwidth of spin excitations in the superconducting CaLa-112 closely resemble to those in 122 systems. While the total fluctuating moments⟨m2⟩≈4.6±0.2μB2/Fe are larger than 122 system, the dynamic correlation lengths are similar (ξ ≈ 10 Å). These results suggest that superconductivity in iron arsenides may have a common magnetic origin under similar magnetic exchange couplings with a dual nature from local moments and itinerant electrons, despite their different magnetic patterns and lattice symmetries.
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Affiliation(s)
- Tao Xie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Chang Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Ryoichi Kajimoto
- Materials and Life Science Division, J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Kazuhiko Ikeuchi
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, Tokai, Ibaraki 319-1106, Japan
| | - Shiliang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Huiqian Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
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2
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Liu C, Bourges P, Sidis Y, Xie T, He G, Bourdarot F, Danilkin S, Ghosh H, Ghosh S, Ma X, Li S, Li Y, Luo H. Preferred Spin Excitations in the Bilayer Iron-Based Superconductor CaK(Fe_{0.96}Ni_{0.04})_{4}As_{4} with Spin-Vortex Crystal Order. PHYSICAL REVIEW LETTERS 2022; 128:137003. [PMID: 35426714 DOI: 10.1103/physrevlett.128.137003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
Spin-orbit coupling (SOC) is a key to understand the magnetically driven superconductivity in iron-based superconductors, where both local and itinerant electrons are present and the orbital angular momentum is not completely quenched. Here, we report a neutron scattering study on the bilayer compound CaK(Fe_{0.96}Ni_{0.04})_{4}As_{4} with superconductivity coexisting with a noncollinear spin-vortex crystal magnetic order that preserves the tetragonal symmetry of the Fe-Fe plane. In the superconducting state, two spin resonance modes with odd and even L symmetries due to the bilayer coupling are found similar to the undoped compound CaKFe_{4}As_{4} but at lower energies. Polarization analysis reveals that the odd mode is c-axis polarized, and the low-energy spin anisotropy can persist to the paramagnetic phase at high temperature, which closely resembles other systems with in-plane collinear and c-axis biaxial magnetic orders. These results provide the missing piece of the puzzle on the SOC effect in iron-pnictide superconductors, and also establish a common picture of c-axis preferred magnetic excitations below T_{c} regardless of the details of magnetic pattern or lattice symmetry.
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Affiliation(s)
- Chang Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Philippe Bourges
- Laboratoire Léon Brillouin, CEA-CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Yvan Sidis
- Laboratoire Léon Brillouin, CEA-CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Tao Xie
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Guanghong He
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | | | - Sergey Danilkin
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, Lucas Heights NSW-2234, Australia
| | - Haranath Ghosh
- Human Resources Development Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, India
- Homi Bhabha National Institute, BARC training school complex 2nd floor, Anushakti Nagar, Mumbai 400094, India
| | - Soumyadeep Ghosh
- Human Resources Development Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, India
- Homi Bhabha National Institute, BARC training school complex 2nd floor, Anushakti Nagar, Mumbai 400094, India
| | - Xiaoyan Ma
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Shiliang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Yuan Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Huiqian Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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3
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Palmstrom JC, Walmsley P, Straquadine JAW, Sorensen ME, Hannahs ST, Burns DH, Fisher IR. Comparison of temperature and doping dependence of elastoresistivity near a putative nematic quantum critical point. Nat Commun 2022; 13:1011. [PMID: 35197491 PMCID: PMC8866430 DOI: 10.1038/s41467-022-28583-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 01/26/2022] [Indexed: 11/25/2022] Open
Abstract
Strong electronic nematic fluctuations have been discovered near optimal doping for several families of Fe-based superconductors, motivating the search for a possible link between these fluctuations, nematic quantum criticality, and high temperature superconductivity. Here we probe a key prediction of quantum criticality, namely power-law dependence of the associated nematic susceptibility as a function of composition and temperature approaching the compositionally tuned putative quantum critical point. To probe the ‘bare’ quantum critical point requires suppression of the superconducting state, which we achieve by using large magnetic fields, up to 45 T, while performing elastoresistivity measurements to follow the nematic susceptibility. We performed these measurements for the prototypical electron-doped pnictide, Ba(Fe1−xCox)2As2, over a dense comb of dopings. We find that close to the putative quantum critical point, the elastoresistivity appears to obey power-law behavior as a function of composition over almost a decade of variation in composition. Paradoxically, however, we also find that the temperature dependence for compositions close to the critical value cannot be described by a single power law. Evidence for quantum criticality in Fe-based superconductors is still being accumulated. Here, the authors observe power-law behavior of the elastoresistivity as a function of composition in Ba(Fe1−xCox)2As2 near a putative nematic quantum critical point, consistent with expectations for quantum criticality, while the temperature dependence near the critical doping deviates from a power law.
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Affiliation(s)
- J C Palmstrom
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, 94305, USA. .,Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA. .,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA. .,National High Magnetic Field Laboratory, Los Alamos, NM, 97545, USA.
| | - P Walmsley
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, 94305, USA.,Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA.,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - J A W Straquadine
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, 94305, USA.,Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA.,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - M E Sorensen
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, 94305, USA.,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.,Department of Physics, Stanford University, Stanford, CA, 94305, USA
| | - S T Hannahs
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - D H Burns
- Department of Geological Sciences, Stanford University, Stanford, CA, 94305, USA
| | - I R Fisher
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, 94305, USA. .,Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA. .,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
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4
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Li L, Parker DS, Gai Z, Cao HB, Sefat AS. Superconductivity with T c ≈ 7 K under pressure for Cu- and Au-doped BaFe 2As 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:295602. [PMID: 32155601 DOI: 10.1088/1361-648x/ab7e60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
It is noteworthy that chemical substitution of BaFe2As2 (122) with the noble elements Cu and Au gives superconductivity with a maximum T c ≈ 3 K, while Ag substitution (Ag-122) stays antiferromagnetic. For Ba(Fe1-x TM x )2As2, TM = Cu, Au, or Ag, and by doping an amount of x = 0.04, a-lattice parameter slightly increases (0.4%) for all TM dopants, while c-lattice decreases (-0.2%) for TM = Cu, barely moves (0.05%) for Au, and increases (0.2%) for Ag. Despite the naive expectation that the noble elements of group 11 should affect the quantum properties of 122 similarly, they produce significant differences extending to the character of the ground state. For the Ag-122 crystal, evidence of only a filamentary superconductivity is noted with pressure. However, for Au and Cu doping (x ≈ 0.03) we find a substantial improvement in the superconductivity, with T c increasing to 7 K and 7.5 K, respectively, under 20 kbar of pressure. As with the ambient pressure results, the identity of the dopant therefore has a substantial impact on the ground state properties. Density functional theory calculations corroborate these results and find evidence of strong electronic scattering for Au and Ag dopants, while Cu is comparatively less disruptive to the 122 electronic structure.
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Affiliation(s)
- Li Li
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
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5
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Ding QP, Meier WR, Cui J, Xu M, Böhmer AE, Bud'ko SL, Canfield PC, Furukawa Y. Hedgehog Spin-Vortex Crystal Antiferromagnetic Quantum Criticality in CaK(Fe_{1-x}Ni_{x})_{4}As_{4} Revealed by NMR. PHYSICAL REVIEW LETTERS 2018; 121:137204. [PMID: 30312082 DOI: 10.1103/physrevlett.121.137204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Indexed: 06/08/2023]
Abstract
Two ordering states, antiferromagnetism and nematicity, have been observed in most iron-based superconductors (SCs). In contrast to those SCs, the newly discovered SC CaK(Fe_{1-x}Ni_{x})_{4}As_{4} exhibits an antiferromagnetic (AFM) state, called hedgehog spin-vortex crystal (SVC) structure, without nematic order, providing the opportunity for the investigation into the relationship between spin fluctuations and SC without any effects of nematic fluctuations. Our ^{75}As nuclear magnetic resonance studies on CaK(Fe_{1-x}Ni_{x})_{4}As_{4} (0≤x≤0.049) revealed that CaKFe_{4}As_{4} is located close to a hidden hedgehog SVC AFM quantum-critical point (QCP). The magnetic QCP without nematicity in CaK(Fe_{1-x}Ni_{x})_{4}As_{4} highlights the close connection of spin fluctuations and superconductivity in iron-based SCs. The advantage of stoichiometric composition also makes CaKFe_{4}As_{4} an ideal platform for further detailed investigation of the relationship between magnetic QCP and superconductivity in iron-based SCs without disorder effects.
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Affiliation(s)
- Q-P Ding
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - W R Meier
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - J Cui
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
| | - M Xu
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - A E Böhmer
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - S L Bud'ko
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - P C Canfield
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Y Furukawa
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
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6
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Wang W, Song Y, Cao C, Tseng KF, Keller T, Li Y, Harriger LW, Tian W, Chi S, Yu R, Nevidomskyy AH, Dai P. Local orthorhombic lattice distortions in the paramagnetic tetragonal phase of superconducting NaFe 1-xNi xAs. Nat Commun 2018; 9:3128. [PMID: 30087342 PMCID: PMC6081486 DOI: 10.1038/s41467-018-05529-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 07/13/2018] [Indexed: 11/08/2022] Open
Abstract
Understanding the interplay between nematicity, magnetism and superconductivity is pivotal for elucidating the physics of iron-based superconductors. Here we use neutron scattering to probe magnetic and nematic orders throughout the phase diagram of NaFe1-xNixAs, finding that while both static antiferromagnetic and nematic orders compete with superconductivity, the onset temperatures for these two orders remain well separated approaching the putative quantum critical points. We uncover local orthorhombic distortions that persist well above the tetragonal-to-orthorhombic structural transition temperature Ts in underdoped samples and extend well into the overdoped regime that exhibits neither magnetic nor structural phase transitions. These unexpected local orthorhombic distortions display Curie-Weiss temperature dependence and become suppressed below the superconducting transition temperature Tc, suggesting that they result from the large nematic susceptibility near optimal superconductivity. Our results account for observations of rotational symmetry breaking above Ts, and attest to the presence of significant nematic fluctuations near optimal superconductivity.
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Affiliation(s)
- Weiyi Wang
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
| | - Yu Song
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
| | - Chongde Cao
- Department of Applied Physics, Northwestern Polytechnical University, Xian, 710072, China.
| | - Kuo-Feng Tseng
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany
- Max Planck Society Outstation at the Forschungsneutronenquelle Heinz Maier-Leibnitz (MLZ), D-85747, Garching, Germany
| | - Thomas Keller
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany
- Max Planck Society Outstation at the Forschungsneutronenquelle Heinz Maier-Leibnitz (MLZ), D-85747, Garching, Germany
| | - Yu Li
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA
| | - L W Harriger
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Wei Tian
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Songxue Chi
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Rong Yu
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing, 100872, China
| | | | - Pengcheng Dai
- Department of Physics and Astronomy, Rice University, Houston, TX, 77005, USA.
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7
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Liu Z, Gu Y, Zhang W, Gong D, Zhang W, Xie T, Lu X, Ma X, Zhang X, Zhang R, Zhu J, Ren C, Shan L, Qiu X, Dai P, Yang YF, Luo H, Li S. Nematic Quantum Critical Fluctuations in BaFe_{2-x}Ni_{x}As_{2}. PHYSICAL REVIEW LETTERS 2016; 117:157002. [PMID: 27768348 DOI: 10.1103/physrevlett.117.157002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Indexed: 06/06/2023]
Abstract
We have systematically studied the nematic fluctuations in the electron-doped iron-based superconductor BaFe_{2-x}Ni_{x}As_{2} by measuring the in-plane resistance change under uniaxial pressure. While the nematic quantum critical point can be identified through the measurements along the (110) direction, as studied previously, quantum and thermal critical fluctuations cannot be distinguished due to similar Curie-Weiss-like behaviors. Here we find that a sizable pressure-dependent resistivity along the (100) direction is present in all doping levels, which is against the simple picture of an Ising-type nematic model. The signal along the (100) direction becomes maximum at optimal doping, suggesting that it is associated with nematic quantum critical fluctuations. Our results indicate that thermal fluctuations from striped antiferromagnetic order dominate the underdoped regime along the (110) direction. We argue that either there is a strong coupling between the quantum critical fluctuations and the fermions, or more exotically, a higher symmetry may be present around optimal doping.
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Affiliation(s)
- Zhaoyu Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yanhong Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wei Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Dongliang Gong
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wenliang Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Tao Xie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xingye Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoyan Ma
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaotian Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Rui Zhang
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1827, USA
| | - Jun Zhu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Cong Ren
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Lei Shan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
| | - Xianggang Qiu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
| | - Pengcheng Dai
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1827, USA
| | - Yi-Feng Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
| | - Huiqian Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shiliang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
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8
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Song Y, Van Dyke J, Lum IK, White BD, Jang S, Yazici D, Shu L, Schneidewind A, Čermák P, Qiu Y, Maple MB, Morr DK, Dai P. Robust upward dispersion of the neutron spin resonance in the heavy fermion superconductor Ce 1-xYb xCoIn 5. Nat Commun 2016; 7:12774. [PMID: 27677397 PMCID: PMC5052703 DOI: 10.1038/ncomms12774] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 07/27/2016] [Indexed: 11/17/2022] Open
Abstract
The neutron spin resonance is a collective magnetic excitation that appears in the unconventional copper oxide, iron pnictide and heavy fermion superconductors. Although the resonance is commonly associated with a spin-exciton due to the d(s±)-wave symmetry of the superconducting order parameter, it has also been proposed to be a magnon-like excitation appearing in the superconducting state. Here we use inelastic neutron scattering to demonstrate that the resonance in the heavy fermion superconductor Ce1-xYbxCoIn5 with x=0, 0.05 and 0.3 has a ring-like upward dispersion that is robust against Yb-doping. By comparing our experimental data with a random phase approximation calculation using the electronic structure and the momentum dependence of the -wave superconducting gap determined from scanning tunnelling microscopy (STM) for CeCoIn5, we conclude that the robust upward-dispersing resonance mode in Ce1-xYbxCoIn5 is inconsistent with the downward dispersion predicted within the spin-exciton scenario.
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Affiliation(s)
- Yu Song
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - John Van Dyke
- Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - I. K. Lum
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, USA
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA
| | - B. D. White
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA
| | - Sooyoung Jang
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, USA
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA
| | - Duygu Yazici
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, USA
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA
| | - L. Shu
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - A. Schneidewind
- Jülich Center for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at MLZ, D-85747 Garching, Germany
| | - Petr Čermák
- Jülich Center for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at MLZ, D-85747 Garching, Germany
| | - Y. Qiu
- NIST Center for Neutron Research, National Institute of Standard and Technology, Gaithersburg, Maryland 20899, USA
| | - M. B. Maple
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, USA
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA
| | - Dirk K. Morr
- Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Pengcheng Dai
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
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9
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Hu D, Lu X, Zhang W, Luo H, Li S, Wang P, Chen G, Han F, Banjara SR, Sapkota A, Kreyssig A, Goldman AI, Yamani Z, Niedermayer C, Skoulatos M, Georgii R, Keller T, Wang P, Yu W, Dai P. Structural and Magnetic Phase Transitions near Optimal Superconductivity in BaFe2(As(1-x)Px)2. PHYSICAL REVIEW LETTERS 2015; 114:157002. [PMID: 25933332 DOI: 10.1103/physrevlett.114.157002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Indexed: 06/04/2023]
Abstract
We use nuclear magnetic resonance (NMR), high-resolution x-ray, and neutron scattering studies to study structural and magnetic phase transitions in phosphorus-doped BaFe2(As(1-x)P(x)2. Previous transport, NMR, specific heat, and magnetic penetration depth measurements have provided compelling evidence for the presence of a quantum critical point (QCP) near optimal superconductivity at x=0.3. However, we show that the tetragonal-to-orthorhombic structural (T{s}) and paramagnetic to antiferromagnetic (AF, TN) transitions in BaFe2(As(1-x)Px)2 are always coupled and approach T{N}≈T{s}≥T{c} (≈29 K) for x=0.29 before vanishing abruptly for x≥0.3. These results suggest that AF order in BaFe_{2}(As(1-x)Px)2 disappears in a weakly first-order fashion near optimal superconductivity, much like the electron-doped iron pnictides with an avoided QCP.
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Affiliation(s)
- Ding Hu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xingye Lu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wenliang Zhang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Huiqian Luo
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shiliang Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Peipei Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Genfu Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fei Han
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Shree R Banjara
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - A Sapkota
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - A Kreyssig
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - A I Goldman
- Ames Laboratory, U.S. DOE, Ames, Iowa 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Z Yamani
- Canadian Neutron Beam Centre, National Research Council, Chalk River, Ontario K0J 1P0, Canada
| | - Christof Niedermayer
- Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Markos Skoulatos
- Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Robert Georgii
- Heinz Maier-Leibnitz Zentrum, Technische Universität München, D-85748 Garching, Germany
| | - T Keller
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
- Max Planck Society Outstation at the Forschungsneutronenquelle Heinz Maier-Leibnitz (MLZ), D-85747 Garching, Germany
| | - Pengshuai Wang
- Department of Physics, Renmin University of China, Beijing 100872, China
| | - Weiqiang Yu
- Department of Physics, Renmin University of China, Beijing 100872, China
| | - Pengcheng Dai
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
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10
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Lu X, Park JT, Zhang R, Luo H, Nevidomskyy AH, Si Q, Dai P. Nematic spin correlations in the tetragonal state of uniaxial-strained BaFe
2−
x
Ni
x
As
2. Science 2014; 345:657-60. [DOI: 10.1126/science.1251853] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Xingye Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J. T. Park
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, D-85748 Garching, Germany
| | - Rui Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Huiqian Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | | | - Qimiao Si
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | - Pengcheng Dai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
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11
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Chen X, Dai P, Feng D, Xiang T, Zhang FC. Iron-based high transition temperature superconductors. Natl Sci Rev 2014. [DOI: 10.1093/nsr/nwu007] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
In a superconductor electrons form pairs and electric transport becomes dissipation-less at low temperatures. Recently discovered iron-based superconductors have the highest superconducting transition temperature next to copper oxides. In this article, we review material aspects and physical properties of iron-based superconductors. We discuss the dependence of transition temperature on the crystal structure, the interplay between antiferromagnetism and superconductivity by examining neutron scattering experiments, and the electronic properties of these compounds obtained by angle-resolved photoemission spectroscopy in link with some results from scanning tunneling microscopy/spectroscopy measurements. Possible microscopic model for this class of compounds is discussed from a strong coupling point of view.
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Affiliation(s)
- Xianhui Chen
- Department of Physics, University of Science and Technology of China, Hefei, 230026, China
| | - Pengcheng Dai
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Donglai Feng
- Department of Physics, Fudan University, Shanghai 200433, China
| | - Tao Xiang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
| | - Fu-Chun Zhang
- Department of Physics, Zhejiang University, Hangzhou, 310027, China
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12
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Luo H, Wang M, Zhang C, Lu X, Regnault LP, Zhang R, Li S, Hu J, Dai P. Spin excitation anisotropy as a probe of orbital ordering in the paramagnetic tetragonal phase of superconducting BaFe1.904Ni0.09As2. PHYSICAL REVIEW LETTERS 2013; 111:107006. [PMID: 25166700 DOI: 10.1103/physrevlett.111.107006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Indexed: 06/03/2023]
Abstract
We use polarized neutron scattering to demonstrate that in-plane spin excitations in electron doped superconducting BaFe1.904Ni0.096As2 (Tc=19.8 K) change from isotropic to anisotropic in the tetragonal phase well above the antiferromagnetic (AFM) ordering and tetragonal-to-orthorhombic lattice distortion temperatures (TN≈Ts=33±2 K) without an uniaxial pressure. While the anisotropic spin excitations are not sensitive to the AFM order and tetragonal-to-orthorhombic lattice distortion, superconductivity induces further anisotropy for spin excitations along the [110] and [110] directions. These results indicate that the spin excitation anisotropy is a probe of the electronic anisotropy or orbital ordering in the tetragonal phase of iron pnictides.
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Affiliation(s)
- Huiqian Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Meng Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Chenglin Zhang
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA and Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA
| | - Xingye Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | | | - Rui Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shiliang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiangping Hu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China and Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA
| | - Pengcheng Dai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China and Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA and Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA
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