1
|
Pikulski M, Shiroka T, Casola F, Reyes AP, Kuhns PL, Wang S, Ott HR, Mesot J. Publisher Correction: Two coupled chains are simpler than one: field-induced chirality in a frustrated spin ladder. Sci Rep 2021; 11:3375. [PMID: 33536588 PMCID: PMC7858614 DOI: 10.1038/s41598-021-82922-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Collapse
Affiliation(s)
- Marek Pikulski
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland
| | - Toni Shiroka
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland. .,Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland.
| | - Francesco Casola
- Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA, 02138, USA
| | - Arneil P Reyes
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Philip L Kuhns
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Shuang Wang
- Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland.,Laboratory for Quantum Magnetism, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
| | - Hans-Rudolf Ott
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland.,Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland
| | - Joël Mesot
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland.,Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland
| |
Collapse
|
2
|
Pikulski M, Shiroka T, Casola F, Reyes AP, Kuhns PL, Wang S, Ott HR, Mesot J. Two coupled chains are simpler than one: field-induced chirality in a frustrated spin ladder. Sci Rep 2020; 10:15862. [PMID: 32985519 PMCID: PMC7522251 DOI: 10.1038/s41598-020-72215-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 05/08/2020] [Indexed: 11/25/2022] Open
Abstract
Although the frustrated (zigzag) spin chain is the Drosophila of frustrated magnetism, our understanding of a pair of coupled zigzag chains (frustrated spin ladder) in a magnetic field is still lacking. We address this problem through nuclear magnetic resonance (NMR) experiments on BiCu\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$_2$$\end{document}2PO\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$_6$$\end{document}6 in magnetic fields up to 45 T, revealing a field-induced spiral magnetic structure. Conjointly, we present advanced numerical calculations showing that even a moderate rung coupling dramatically simplifies the phase diagram below half-saturation magnetization by stabilizing a field-induced chiral phase. Surprisingly for a one-dimensional model, this phase and its response to Dzyaloshinskii-Moriya (DM) interactions adhere to classical expectations. While explaining the behavior at the highest accessible magnetic fields, our results imply a different origin for the solitonic phases occurring at lower fields in BiCu\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$_2$$\end{document}2PO\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$_6$$\end{document}6. An exciting possibility is that the known, DM-mediated coupling between chirality and crystal lattice may give rise to a new kind of spin-Peierls instability.
Collapse
Affiliation(s)
- Marek Pikulski
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland
| | - Toni Shiroka
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland. .,Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland.
| | - Francesco Casola
- Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA, 02138, USA
| | - Arneil P Reyes
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Philip L Kuhns
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Shuang Wang
- Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland.,Laboratory for Quantum Magnetism, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
| | - Hans-Rudolf Ott
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland.,Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland
| | - Joël Mesot
- Laboratory for Solid State Physics, ETH Zürich, 8093, Zürich, Switzerland.,Paul Scherrer Institut, Villigen PSI, 5232, Villigen, Switzerland
| |
Collapse
|
3
|
Kawasaki S, Li Z, Kitahashi M, Lin CT, Kuhns PL, Reyes AP, Zheng GQ. Charge-density-wave order takes over antiferromagnetism in Bi 2Sr 2-x La x CuO 6 superconductors. Nat Commun 2017; 8:1267. [PMID: 29097672 PMCID: PMC5668353 DOI: 10.1038/s41467-017-01465-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 09/19/2017] [Indexed: 11/17/2022] Open
Abstract
Superconductivity appears in the cuprates when a spin order is destroyed, while the role of charge is less known. Recently, charge density wave (CDW) was found below the superconducting dome in YBa2Cu3Oy when a high magnetic field is applied perpendicular to the CuO2 plane, which was suggested to arise from incipient CDW in the vortex cores that becomes overlapped. Here by 63Cu-nuclear magnetic resonance, we report the discovery of CDW induced by an in-plane field, setting in above the dome in single-layered Bi2Sr2−xLaxCuO6. The onset temperature TCDW takes over the antiferromagnetic order temperature TN beyond a critical doping level at which superconductivity starts to emerge, and scales with the pseudogap temperature T*. These results provide important insights into the relationship between spin order, CDW and the pseudogap, and their connections to high-temperature superconductivity. Whilst superconductivity usually appears when magnetic order is suppressed, the role of charge is less known. Here, Kawasaki et al. report a charge density wave (CDW) above the superconducting transition induced by an in-plane magnetic field in Bi2Sr2-xLaxCuO6, with the CDW onset temperature scaling with the pseudogap temperature.
Collapse
Affiliation(s)
- S Kawasaki
- Department of Physics, Okayama University, Okayama, 700-8530, Japan
| | - Z Li
- Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, 100190, Beijing, China
| | - M Kitahashi
- Department of Physics, Okayama University, Okayama, 700-8530, Japan
| | - C T Lin
- Max-Planck-Institut fur Festkorperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany
| | - P L Kuhns
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - A P Reyes
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Guo-Qing Zheng
- Department of Physics, Okayama University, Okayama, 700-8530, Japan. .,Institute of Physics, Chinese Academy of Sciences, and Beijing National Laboratory for Condensed Matter Physics, 100190, Beijing, China.
| |
Collapse
|
4
|
Zhou R, Hirata M, Wu T, Vinograd I, Mayaffre H, Krämer S, Horvatić M, Berthier C, Reyes AP, Kuhns PL, Liang R, Hardy WN, Bonn DA, Julien MH. Quasiparticle Scattering off Defects and Possible Bound States in Charge-Ordered YBa_{2}Cu_{3}O_{y}. Phys Rev Lett 2017; 118:017001. [PMID: 28106424 DOI: 10.1103/physrevlett.118.017001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Indexed: 06/06/2023]
Abstract
We report the NMR observation of a skewed distribution of ^{17}O Knight shifts when a magnetic field quenches superconductivity and induces long-range charge-density-wave (CDW) order in YBa_{2}Cu_{3}O_{y}. This distribution is explained by an inhomogeneous pattern of the local density of states N(E_{F}) arising from quasiparticle scattering off, yet unidentified, defects in the CDW state. We argue that the effect is most likely related to the formation of quasiparticle bound states, as is known to occur, under specific circumstances, in some metals and superconductors (but not in the CDW state, in general, except for very few cases in 1D materials). These observations should provide insight into the microscopic nature of the CDW, especially regarding the reconstructed band structure and the sensitivity to disorder.
Collapse
Affiliation(s)
- R Zhou
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - M Hirata
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - T Wu
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - I Vinograd
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - H Mayaffre
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - S Krämer
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - M Horvatić
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - C Berthier
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-UPS-INSA-EMFL, 38042 Grenoble, France
| | - A P Reyes
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - P L Kuhns
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - R Liang
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Canadian Institute for Advanced Research, Toronto M5G 1Z8, Canada
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Canadian Institute for Advanced Research, Toronto M5G 1Z8, Canada
| | - D A Bonn
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Canadian Institute for Advanced Research, Toronto M5G 1Z8, Canada
| | - M-H Julien
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Université Grenoble Alpes-EMFL, 38042 Grenoble, France
| |
Collapse
|
5
|
Wu G, Greene RL, Reyes AP, Kuhns PL, Moulton WG, Wu B, Wu F, Clark WG. Superconducting anisotropy in the electron-doped high-Tc superconductors Pr2-xCexCuO4-y. J Phys Condens Matter 2014; 26:405701. [PMID: 25219526 DOI: 10.1088/0953-8984/26/40/405701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report superconducting anisotropy measurements in the electron-doped high-Tc superconductors (HTSCs) Pr(2-x)Ce(x)C(u)O(4-y) (PCCO, x = 0.15 and 0.17) with an applied magnetic field (H0) up to 28 T. Our results show that the upper critical field [H(c2)(T)] of PCCO is highly anisotropic and as the temperature T → 0, the value of it at H0 ∥ c [H(c2,∥c)(0)] is far less than the Pauli limit. The low temperature anisotropic character of PCCO is found to be rather similar to that of hole-doped cuprate HTSCs, but apparently larger than that of typical Fe-based superconductors. This study also proves a new sensitive probe of detecting rich properties of unconventional superconductors with the use of the resonant frequency of an NMR probe circuit.
Collapse
Affiliation(s)
- Guoqing Wu
- College of Physics Science and Technology, Yangzhou University, Yangzhou, Jiangsu 225002, People's Republic of China. Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Sakai H, Tokunaga Y, Kambe S, Urbano RR, Suzuki MT, Kuhns PL, Reyes AP, Tobash PH, Ronning F, Bauer ED, Thompson JD. Emergent antiferromagnetism out of the "hidden-order" state in URu2Si2: high magnetic field nuclear magnetic resonance to 40 T. Phys Rev Lett 2014; 112:236401. [PMID: 24972218 DOI: 10.1103/physrevlett.112.236401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Indexed: 06/03/2023]
Abstract
Very high field (29)Si-NMR measurements using a fully (29)Si-enriched URu(2)Si(2) single crystal were carried out in order to microscopically investigate the "hidden order" (HO) state and adjacent magnetic phases in the high field limit. At the lowest measured temperature of 0.4 K, a clear anomaly reflecting a Fermi surface instability near 22 T inside the HO state is detected by the (29)Si shift, (29)K(c). Moreover, a strong enhancement of (29)K(c) develops near a critical field H(c) ≃ 35.6 T, and the ^{29}Si-NMR signal disappears suddenly at H(c), indicating the total suppression of the HO state. Nevertheless, a weak and shifted (29)Si-NMR signal reappears for fields higher than H(c) at 4.2 K, providing evidence for a magnetic structure within the magnetic phase caused by the Ising-type anisotropy of the uranium ordered moments.
Collapse
Affiliation(s)
- H Sakai
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Y Tokunaga
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - S Kambe
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - R R Urbano
- Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas, 13083-859 Campinas, SP, Brazil and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - M-T Suzuki
- CCSE, Japan Atomic Energy Agency, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8587, Japan
| | - P L Kuhns
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - A P Reyes
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - P H Tobash
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F Ronning
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E D Bauer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J D Thompson
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| |
Collapse
|
7
|
Wu T, Mayaffre H, Krämer S, Horvatić M, Berthier C, Kuhns PL, Reyes AP, Liang R, Hardy WN, Bonn DA, Julien MH. Emergence of charge order from the vortex state of a high-temperature superconductor. Nat Commun 2013; 4:2113. [PMID: 23820931 DOI: 10.1038/ncomms3113] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 06/05/2013] [Indexed: 11/09/2022] Open
Abstract
Evidence is mounting that charge order competes with superconductivity in high Tc cuprates. Whether this has any relationship to the pairing mechanism is unknown as neither the universality of the competition nor its microscopic nature has been established. Here, we show using nuclear magnetic resonance that charge order in YBa2Cu3Oy has maximum strength inside the superconducting dome, similar to compounds of the La2-x(Sr,Ba)xCuO4 family. In YBa2Cu3Oy, this occurs at doping levels of p=0.11-0.12. We further show that the overlap of halos of incipient charge order around vortex cores, similar to those visualised in Bi2Sr2CaCu2O8+δ, can explain the threshold magnetic field at which long-range charge order emerges. These results reveal universal features of a competition in which charge order and superconductivity appear as joint instabilities of the same normal state, whose relative balance can be field-tuned in the vortex state.
Collapse
Affiliation(s)
- Tao Wu
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, Grenoble, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Mounce AM, Oh S, Lee JA, Halperin WP, Reyes AP, Kuhns PL, Chan MK, Dorow C, Ji L, Xia D, Zhao X, Greven M. Absence of static loop-current magnetism at the apical oxygen site in HgBa2CuO4+δ from NMR. Phys Rev Lett 2013; 111:187003. [PMID: 24237553 DOI: 10.1103/physrevlett.111.187003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Indexed: 06/02/2023]
Abstract
The simple structure of HgBa(2)CuO(4+δ) (Hg1201) is ideal among cuprates for study of the pseudogap phase as a broken symmetry state. We have performed (17)O nuclear magnetic resonance on an underdoped Hg1201 crystal with a transition temperature of 74 K to look for circulating loop currents proposed theoretically and inferred from neutron scattering. The narrow spectra preclude static local fields in the pseudogap phase at the apical site, suggesting that the moments observed with neutrons are fluctuating. The nuclear magnetic resonance frequency shifts are consistent with a dipolar field from the Cu(2+) site.
Collapse
Affiliation(s)
- A M Mounce
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Lampropoulos C, Murugesu M, Harter AG, Wernsdofer W, Hill S, Dalal NS, Reyes AP, Kuhns PL, Abboud KA, Christou G. Synthesis, Structure, and Spectroscopic and Magnetic Characterization of [Mn12O12(O2CCH2But)16(MeOH)4]·MeOH, a Mn12 Single-Molecule Magnet with True Axial Symmetry. Inorg Chem 2012; 52:258-72. [DOI: 10.1021/ic301764t] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christos Lampropoulos
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Muralee Murugesu
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Andrew G. Harter
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32310,
United States
| | - Wolfgang Wernsdofer
- Institut Néel, CNRS/UJF, BP 166, 25 Avenue des Martyrs,
38042, Grenoble, Cedex 9, France
| | - Stephen Hill
- Department
of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310,
United States
| | - Naresh S. Dalal
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32310,
United States
| | - Arneil P. Reyes
- Department
of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310,
United States
| | - Philip L. Kuhns
- Department
of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310,
United States
| | - Khalil A. Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| |
Collapse
|
10
|
Besara T, Jain P, Dalal NS, Kuhns PL, Reyes AP, Kroto HW, Cheetham AK. Mechanism of the order–disorder phase transition, and glassy behavior in the metal-organic framework [(CH 3) 2NH 2]Zn(HCOO) 3. Proc Natl Acad Sci U S A 2011; 108:6828-6832. [PMCID: PMC3084146 DOI: 10.1073/pnas.1102079108] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024] Open
Abstract
Transitions associated with orientational order–disorder phenomena are found in a wide range of materials and may have a significant impact on their properties. In this work, specific heat and 1H NMR measurements have been used to study the phase transition in the metal-organic framework (MOF) compound [(CH3)2NH2]Zn(HCOO)3. This compound, which possesses a perovskite-type architecture, undergoes a remarkable order–disorder phase transition at 156 K. The (DMA+) cationic moieties that are bound by hydrogen bonds to the oxygens of the formate groups (N─H⋯O ∼ 2.9 Å ) are essentially trapped inside the basic perovskite cage architecture. Above 156 K, it is the orientations of these moieties that are responsible for the disorder, as each can take up three different orientations with equal probability. Below 156 K, the DMA+ is ordered within one of these sites, although the moiety still retains a considerable state of motion. Below 40 K, the rotational motions of the methyl groups start to freeze. As the temperature is increased from 4 K in the NMR measurements, different relaxation pathways can be observed in the temperature range approximately 65–150 K, as a result of a “memory effect.” This dynamic behavior is characteristic of a glass in which multiple states possess similar energies, found here for a MOF. This conclusion is strongly supported by the specific heat data.
Collapse
Affiliation(s)
- Tiglet Besara
- National High Magnetic Field Laboratory, Tallahassee, FL 32310
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306; and
| | - Prashant Jain
- National High Magnetic Field Laboratory, Tallahassee, FL 32310
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306; and
| | - Naresh S. Dalal
- National High Magnetic Field Laboratory, Tallahassee, FL 32310
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306; and
| | - Philip L. Kuhns
- National High Magnetic Field Laboratory, Tallahassee, FL 32310
| | - Arneil P. Reyes
- National High Magnetic Field Laboratory, Tallahassee, FL 32310
| | - Harold W. Kroto
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306; and
| | - Anthony K. Cheetham
- Department of Materials and Metallurgy, University of Cambridge, Cambridge CB2 3QZ, United Kingdom
| |
Collapse
|
11
|
Mounce AM, Oh S, Mukhopadhyay S, Halperin WP, Reyes AP, Kuhns PL, Fujita K, Ishikado M, Uchida S. Spin-density wave near the vortex cores in the high-temperature superconductor Bi2Sr2CaCu2O8+y. Phys Rev Lett 2011; 106:057003. [PMID: 21405423 DOI: 10.1103/physrevlett.106.057003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 12/23/2010] [Indexed: 05/30/2023]
Abstract
Competition with magnetism is at the heart of high-temperature superconductivity, most intensely felt near a vortex core. To investigate vortex magnetism we have developed a spatially resolved probe based upon NMR spin-lattice-relaxation spectroscopy. With this approach we have found a spin-density wave associated with the vortex core in Bi(2)Sr(2)CaCu(2)O(8+y), similar to checkerboard patterns in the local density of electronic states reported from scanning tunneling microscope experiments. We have determined both the spin-modulation amplitude and decay length from the vortex core in fields up to H=30 T.
Collapse
Affiliation(s)
- A M Mounce
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Kawasaki S, Lin C, Kuhns PL, Reyes AP, Zheng GQ. Carrier-concentration dependence of the pseudogap ground state of superconducting Bi₂Sr(₂-x)La(x)CuO(₆+δ) revealed by ⁶³,⁶⁵Cu-nuclear magnetic resonance in very high magnetic fields. Phys Rev Lett 2010; 105:137002. [PMID: 21230801 DOI: 10.1103/physrevlett.105.137002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 06/30/2010] [Indexed: 05/30/2023]
Abstract
We report the results of the Knight shift by ⁶³,⁶⁵Cu-NMR measurements on single-layered copper-oxide Bi₂Sr(₂-x)La(x)CuO(₆+δ) conducted under very high magnetic fields up to 44 T. The magnetic field suppresses superconductivity completely, and the pseudogap ground state is revealed. The ⁶³Cu-NMR Knight shift shows that there remains a finite density of states at the Fermi level in the zero-temperature limit, which indicates that the pseudogap ground state is a metallic state with a finite volume of Fermi surface. The residual density of states in the pseudogap ground state decreases with decreasing doping (increasing x) but remains quite large even at the vicinity of the magnetically ordered phase of x ≥ 0.8, which suggests that the density of states plunges to zero upon approaching the Mott insulating phase.
Collapse
Affiliation(s)
- Shinji Kawasaki
- Department of Physics, Okayama University, Okayama 700-8530, Japan
| | | | | | | | | |
Collapse
|
13
|
Urbano RR, Green EL, Moulton WG, Reyes AP, Kuhns PL, Bittar EM, Adriano C, Garitezi TM, Bufaiçal L, Pagliuso PG. Distinct high-T transitions in underdoped Ba(1-x)KxFe2As2. Phys Rev Lett 2010; 105:107001. [PMID: 20867539 DOI: 10.1103/physrevlett.105.107001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Indexed: 05/29/2023]
Abstract
In contrast with the simultaneous structural and magnetic first order phase transition T0 previously reported, our detailed investigation on an underdoped Ba(0.84)K(0.16)Fe2As2 single crystal unambiguously revealed that the transitions are not concomitant. The tetragonal (τ: I4/mmm)-orthorhombic (ϑ: Fmmm) structural transition occurs at T(S)≃110 K, followed by an adjacent long-range antiferromagnetic (AFM) transition at T(N)≃102 K. Hysteresis and coexistence of the τ and ϑ phases over a finite temperature range observed by NMR experiments confirm the first order character of the τ-ϑ transition and provide evidence that both T(S) and T(N) are strongly correlated. Our data also show that superconductivity develops in the ϑ phase below T(c)=20 K and coexists with AFM. This new observation, T(S)≠T(N), firmly establishes another similarity between the hole-doped BaFe2As2 and the electron-doped iron-arsenide superconductors.
Collapse
Affiliation(s)
- R R Urbano
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306-4005, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Lumata LL, Choi KY, Brooks JS, Reyes AP, Kuhns PL, Wu G, Chen XH. 77Se and 63Cu NMR studies of the electronic correlations in CuxTiSe2 (x = 0.05, 0.07). J Phys Condens Matter 2010; 22:295601. [PMID: 21399313 DOI: 10.1088/0953-8984/22/29/295601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report a (77)Se and (63)Cu nuclear magnetic resonance (NMR) investigation on the charge-density-wave (CDW) superconductor Cu(x)TiSe(2) (x = 0.05 and 0.07). At high magnetic fields where superconductivity is suppressed, the temperature dependence of (77)Se and (63)Cu spin-lattice relaxation rates 1/T(1) follow a linear relation. The slope of (77)Se 1/T(1) versus T increases with the Cu doping. This can be described by a modified Korringa relation which suggests the significance of electronic correlations and the Se 4p- and Ti 3d-band contribution to the density of states at the Fermi level in the studied compounds.
Collapse
Affiliation(s)
- L L Lumata
- Department of Physics, Florida State University, Tallahassee, FL 32310, USA.
| | | | | | | | | | | | | |
Collapse
|
15
|
Zhou HD, Wiebe CR, Jo YJ, Balicas L, Urbano RR, Lumata LL, Brooks JS, Kuhns PL, Reyes AP, Qiu Y, Copley JRD, Gardner JS. Chemical pressure induced spin freezing phase transition in kagome pr langasites. Phys Rev Lett 2009; 102:067203. [PMID: 19257628 DOI: 10.1103/physrevlett.102.067203] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2008] [Revised: 12/12/2008] [Indexed: 05/27/2023]
Abstract
The 2D kagome system Pr3Ga5SiO14 has been previously identified as a spin-liquid candidate in zero field, displaying no magnetic long-ranged order down to at least 35 mK. Perturbations upon such systems, either under applied fields or applied pressure, should induce a spin freezing phase transition, but there are very few experimental realizations of this phenomena other than the well-studied 3D pyrochlore Tb2Ti2O7. In this Letter, we report the observation of a spin freezing phase transition in Pr3Ga5SiO14 through the application of chemical pressure--that is, through a systematic substitution on the Si site with larger ions and an elongation of the nearest-neighbor Pr-Pr distance in the kagome lattice. This results in a suppression of the T2 component of the heat capacity, and the reduction of the exchange constant eventually leads to dipolar-driven spin freezing.
Collapse
Affiliation(s)
- H D Zhou
- Department of Physics, Florida State University, Tallahassee, Florida 32306-3016, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Leighton C, Manno M, Cady A, Freeland JW, Wang L, Umemoto K, Wentzcovitch RM, Chen TY, Chien CL, Kuhns PL, Hoch MJR, Reyes AP, Moulton WG, Dahlberg ED, Checkelsky J, Eckert J. Composition controlled spin polarization in Co(1-x)Fe(x)S(2) alloys. J Phys Condens Matter 2007; 19:315219. [PMID: 21694119 DOI: 10.1088/0953-8984/19/31/315219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The transition metal (TM) chalcogenides of the form TMX(2) (X = S or Se) have been studied for decades due to their interesting electronic and magnetic properties such as metamagnetism and metal-insulator transitions. In particular, the Co(1-x)Fe(x)S(2) alloys were the subject of investigation in the 1970s due to general interest in itinerant ferromagnetism. In recent years (2000-present) it has been shown, both by electronic structure calculations and detailed experimental investigations, that Co(1-x)Fe(x)S(2) is a model system for the investigation of highly spin polarized ferromagnetism. The radically different electronic properties of the two endpoint compounds (CoS(2) is a narrow bandwidth ferromagnetic metal, while FeS(2) is a diamagnetic semiconductor), in a system forming a substitutional solid solution allows for composition control of the Fermi level relative to the spin split bands, and therefore composition-controlled conduction electron spin polarization. In essence, the recent work has shown that the concept of 'band engineering' can be applied to half-metallic ferromagnets and that high spin polarization can be deliberately engineered. Experiments reveal tunability in both sign and magnitude of the spin polarization at the Fermi level, with maximum values obtained to date of 85% at low temperatures. In this paper we review the properties of Co(1-x)Fe(x)S(2) alloys, with an emphasis on properties of relevance to half-metallicity. Crystal structure, electronic structure, synthesis, magnetic properties, transport properties, direct probes of the spin polarization, and measurements of the total density of states at the Fermi level are all discussed. We conclude with a discussion of the factors that influence, or even limit, the spin polarization, along with a discussion of opportunities and problems for future investigation, particularly with regard to fundamental studies of spintronic devices.
Collapse
Affiliation(s)
- C Leighton
- Department of Chemical Engineering and Materials Science, University of Minnesota, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Chakov NE, Lee SC, Harter AG, Kuhns PL, Reyes AP, Hill SO, Dalal NS, Wernsdorfer W, Abboud KA, Christou G. The Properties of the [Mn12O12(O2CR)16(H2O)4] Single-Molecule Magnets in Truly Axial Symmetry: [Mn12O12(O2CCH2Br)16(H2O)4]·4CH2Cl2. J Am Chem Soc 2006; 128:6975-89. [PMID: 16719478 DOI: 10.1021/ja060796n] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Detailed studies are reported of a Mn(12) single-molecule magnet (SMM) in truly axial (tetragonal) symmetry. The complex is [Mn(12)O(12)(O(2)CCH(2)Br)(16)(H(2)O)(4)].4CH(2)Cl(2) (2.4CH(2)Cl(2) or Mn(12)-BrAc), obtained by the standard carboxylate substitution method. The complex has an S = 10 ground state, typical of the Mn(12) family, and displays frequency-dependent out-of-phase AC susceptibility signals and hysteresis in single-crystal magnetization vs applied DC field sweeps. Single-crystal high-frequency EPR spectra in frequencies up to 360 GHz exhibit narrow signals that are not overlapping multiplets, in contrast to [Mn(12)O(12)(O(2)CMe)(16)(H(2)O)(4)].2MeCO(2)H.4H(2)O (1 or Mn(12)-Ac), which also crystallizes in an axial (tetragonal) space group but which now is recognized to consist of a mixture of six hydrogen-bonded isomers in the crystal and thus gives multiple, inhomogeneously broadened EPR signals. Similarly, single-crystal (55)Mn NMR spectra on Mn(12)-BrAc display much sharper signals than a single crystal of Mn(12)-Ac, and this allows one Mn(III) signal to show an almost baseline-resolved quintet from quadrupolar splitting ((55)Mn, I = 5/2, 100%), allowing quadrupole coupling parameters (e(2)qQ) to be determined. In addition, it was found that crushing crystals of Mn(12)-BrAc into a microcrystalline powder causes severe broadening and shifts of the NMR resonances, emphasizing the superiority of single-crystal studies. The combined results establish that Mn(12)-BrAc is far superior to Mn(12)-Ac for the study of the intrinsic properties of the Mn(12) family of SMMs in axial symmetry, and for the search for new phenomena such as quantum interference effects caused by higher-order (>2nd-order) transverse terms in the spin Hamiltonian.
Collapse
Affiliation(s)
- Nicole E Chakov
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Kuhns PL, Hoch MJR, Reyes AP, Moulton WG, Wang L, Leighton C. Evolution with composition of the d-band density of states at the Fermi level in highly spin polarized Co1-xFexS2. Phys Rev Lett 2006; 96:167208. [PMID: 16712272 DOI: 10.1103/physrevlett.96.167208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 01/30/2006] [Indexed: 05/09/2023]
Abstract
Highly spin polarized (SP) and half-metallic ferromagnetic systems are of considerable current interest and of potential importance for spintronic applications. Recent work has demonstrated that Co1-xFexS2 is a highly polarized ferromagnet (FM) where the spin polarization can be tuned by alloy composition. Using 59Co FM-NMR as a probe, we have measured the low-temperature spin relaxation in this system in magnetic fields from 0 to 1.0 T for 0<or=x<or=0.3. The 59Co spin-lattice relaxation rates follow a linear T dependence. Analysis of the data, using expressions for a FM system, permits information to be obtained on the d-band density of states at the Fermi level. The results are compared with independent density of states values inferred from electronic specific heat measurements and band structure calculations. It is shown that FM-NMR can be an important method for investigating highly SP systems.
Collapse
Affiliation(s)
- P L Kuhns
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | | | | | | | | | | |
Collapse
|
19
|
Gervais G, Stormer HL, Tsui DC, Kuhns PL, Moulton WG, Reyes AP, Pfeiffer LN, Baldwin KW, West KW. Evidence for skyrmion crystallization from NMR relaxation experiments. Phys Rev Lett 2005; 94:196803. [PMID: 16090197 DOI: 10.1103/physrevlett.94.196803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2004] [Indexed: 05/03/2023]
Abstract
A resistively detected NMR technique was used to probe the two-dimensional electron gas in a GaAs/AlGaAs quantum well. The spin-lattice relaxation rate (1/T(1)) was extracted at near complete filling of the first Landau level by electrons. The nuclear spin of (75)As is found to relax much more efficiently with T --> 0 and when a well developed quantum Hall state with R(xx) approximately 0 occurs. The data show a remarkable correlation between the nuclear spin relaxation and localization. This suggests that the magnetic ground state near complete filling of the first Landau level may contain a lattice of topological spin texture, i.e., a Skyrmion crystal.
Collapse
Affiliation(s)
- G Gervais
- Department of Physics, Columbia University, New York, New York 10027 USA
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Zheng GQ, Kuhns PL, Reyes AP, Liang B, Lin CT. Critical point and the nature of the pseudogap of single-layered copper-oxide Bi2Sr2-xLaxCuO6+delta superconductors. Phys Rev Lett 2005; 94:047006. [PMID: 15783588 DOI: 10.1103/physrevlett.94.047006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Indexed: 05/24/2023]
Abstract
We apply strong magnetic fields of H=28.5 to 43 T to suppress superconductivity (SC) in the cuprates Bi2Sr2-xLaxCuO6+delta (x=0.65, 0.40, 0.25, 0.15, and 0), and investigate the low temperature (T) normal state by 63Cu nuclear spin-lattice relaxation rate (1/T1) measurements. We find that the pseudogap (PG) phase persists deep inside the overdoped region but terminates at x approximately 0.05, which corresponds to the hole doping concentration of approximately 0.21. Beyond this critical point, the normal state is a Fermi liquid that persists as the ground state when superconductivity is removed by the magnetic field. A comparison of the superconducting state with the H-induced normal state in the x=0.40 (Tc=32 K) sample indicates that there remains substantial part of the Fermi surface even in the fully developed PG state, which suggests that the PG and SC are coexisting matters.
Collapse
Affiliation(s)
- Guo-Qing Zheng
- Department of Physics, Okayama University, Okayama 700-8530, Japan
| | | | | | | | | |
Collapse
|
21
|
Kuhns PL, Hoch MJR, Moulton WG, Reyes AP, Wu J, Leighton C. Magnetic phase separation in La1-xSrxCoO3 by 59Co nuclear magnetic resonance. Phys Rev Lett 2003; 91:127202. [PMID: 14525396 DOI: 10.1103/physrevlett.91.127202] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2003] [Indexed: 05/24/2023]
Abstract
59Co NMR measurements on La1-xSrxCoO3 reported here establish unequivocally, for the first time, the coexistence of ferromagnetic regions, spin-glass regions, and hole-poor low spin regions at all x values from 0.1 to 0.5. A zero external field NMR spectrum, which is assigned to the ferromagnetic regions, has a spectral shape that is nearly x independent at 1.9 K, as are the relaxation times, T1 and T2. The integrated spectral area increases rapidly with x up to x = 0.2 and then decreases slightly for larger x. In a field of 9.97 T, a narrow NMR line is observed at 102 MHz, identical to that found in x = 0 samples in previous work. The integrated intensity of this spectrum decreases rapidly with increasing x, and is ascribed to hole-poor low spin regions. Beneath this spectrum, a third broad line, with a peak at 100 MHz, is assigned to a spin- or cluster-glass-like phase.
Collapse
Affiliation(s)
- P L Kuhns
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
| | | | | | | | | | | |
Collapse
|
22
|
Sigmund EE, Calder ES, Thomas GW, Mitrović VF, Bachman HN, Halperin WP, Kuhns PL, Reyes AP. NMR phase noise in bitter magnets. J Magn Reson 2001; 148:309-13. [PMID: 11237636 DOI: 10.1006/jmre.2000.2246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We have studied the temporal instability of a high field resistive Bitter magnet through nuclear magnetic resonance (NMR). This instability leads to transverse spin decoherence in repeated and accumulated NMR experiments as is normally performed during signal averaging. We demonstrate this effect via Hahn echo and Carr--Purcell--Meiboom--Gill (CPMG) transverse relaxation experiments in a 23-T resistive magnet. Quantitative analysis was found to be consistent with separate measurements of the magnetic field frequency fluctuation spectrum, as well as with independent NMR experiments performed in a magnetic field with a controlled instability. Finally, the CPMG sequence with short pulse delays is shown to be successful in recovering the intrinsic spin--spin relaxation even in the presence of magnetic field temporal instability.
Collapse
Affiliation(s)
- E E Sigmund
- Department of Physics, Northwestern University, Evanston, Illinois 60208, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
|
24
|
|
25
|
Kuhns PL, Hammel PC, Gonen O, Waugh JS. Unexpectedly rapid 19F spin-lattice relaxation in CaF2 below 1 K. Phys Rev B Condens Matter 1987; 35:4591-4593. [PMID: 9940628 DOI: 10.1103/physrevb.35.4591] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
|
26
|
|
27
|
|
28
|
|
29
|
|