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Dashwood CD, Walker AH, Kwasigroch MP, Veiga LSI, Faure Q, Vale JG, Porter DG, Manuel P, Khalyavin DD, Orlandi F, Colin CV, Fabelo O, Krüger F, Perry RS, Johnson RD, Green AG, McMorrow DF. Strain control of a bandwidth-driven spin reorientation in Ca 3Ru 2O 7. Nat Commun 2023; 14:6197. [PMID: 37794061 PMCID: PMC10550943 DOI: 10.1038/s41467-023-41714-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 09/15/2023] [Indexed: 10/06/2023] Open
Abstract
The layered-ruthenate family of materials possess an intricate interplay of structural, electronic and magnetic degrees of freedom that yields a plethora of delicately balanced ground states. This is exemplified by Ca3Ru2O7, which hosts a coupled transition in which the lattice parameters jump, the Fermi surface partially gaps and the spins undergo a 90∘ in-plane reorientation. Here, we show how the transition is driven by a lattice strain that tunes the electronic bandwidth. We apply uniaxial stress to single crystals of Ca3Ru2O7, using neutron and resonant x-ray scattering to simultaneously probe the structural and magnetic responses. These measurements demonstrate that the transition can be driven by externally induced strain, stimulating the development of a theoretical model in which an internal strain is generated self-consistently to lower the electronic energy. We understand the strain to act by modifying tilts and rotations of the RuO6 octahedra, which directly influences the nearest-neighbour hopping. Our results offer a blueprint for uncovering the driving force behind coupled phase transitions, as well as a route to controlling them.
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Affiliation(s)
- C D Dashwood
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
| | - A H Walker
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
| | - M P Kwasigroch
- Department of Mathematics, University College London, London, WC1H 0AY, UK
- Trinity College, Cambridge, CB2 1TQ, UK
| | - L S I Veiga
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Q Faure
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
- Laboratoire León Brillouin, CEA, CNRS, Université Paris-Saclay, CEA-Saclay, 91191, Gif-sur-Yvette, France
| | - J G Vale
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
| | - D G Porter
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - P Manuel
- ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire, OX11 0QX, UK
| | - D D Khalyavin
- ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire, OX11 0QX, UK
| | - F Orlandi
- ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire, OX11 0QX, UK
| | - C V Colin
- Université Grenoble Alpes, CNRS, Institut Néel, 38000, Grenoble, France
| | - O Fabelo
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042, Grenoble, France
| | - F Krüger
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
- ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire, OX11 0QX, UK
| | - R S Perry
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
| | - R D Johnson
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
| | - A G Green
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
| | - D F McMorrow
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
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Nilsen GJ, Arslan S, Cassella G, Perry RS, Goff JP, Voneshen DJ. Publisher's Note: "z +: Neutron cross section separation from wide-angle uniaxial polarization analysis" [Rev. Sci. Instrum. 93, 063902 (2022)]. Rev Sci Instrum 2022; 93:079901. [PMID: 35922302 DOI: 10.1063/5.0103168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Indexed: 06/15/2023]
Affiliation(s)
- G J Nilsen
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - S Arslan
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - G Cassella
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - R S Perry
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - J P Goff
- Department of Physics, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom
| | - D J Voneshen
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
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Nilsen GJ, Arslan S, Cassella G, Perry RS, Goff JP, Voneshen DJ. z +: Neutron cross section separation from wide-angle uniaxial polarization analysis. Rev Sci Instrum 2022; 93:063902. [PMID: 35778005 DOI: 10.1063/5.0084347] [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: 01/05/2022] [Accepted: 04/23/2022] [Indexed: 06/15/2023]
Abstract
We introduce a simple method to extract the nuclear coherent and isotope incoherent, spin incoherent, and magnetic neutron scattering cross section components from powder scattering data measured using a single neutron beam polarization direction and a position-sensitive detector with large out-of-plane coverage. The method draws inspiration from polarized small-angle neutron scattering and contrasts with conventional so-called "xyz" polarization analysis on wide-angle instruments, which requires measurements with three orthogonal polarization directions. The viability of the method is demonstrated on both simulated and experimental data for the classical "spin ice" system Ho2Ti2O7, the latter from the LET direct geometry spectrometer at the ISIS facility. The cross section components can be reproduced with good fidelity by either fitting the out-of-plane angle dependence around a Debye-Scherrer cone or grouping the data by angle and performing a matrix inversion. The limitations of the method and its practical uses are discussed.
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Affiliation(s)
- G J Nilsen
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - S Arslan
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - G Cassella
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - R S Perry
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - J P Goff
- Department of Physics, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom
| | - D J Voneshen
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
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Lester C, Ramos S, Perry RS, Croft TP, Laver M, Bewley RI, Guidi T, Hiess A, Wildes A, Forgan EM, Hayden SM. Magnetic-field-controlled spin fluctuations and quantum critically in Sr 3Ru 2O 7. Nat Commun 2021; 12:5798. [PMID: 34608160 PMCID: PMC8490391 DOI: 10.1038/s41467-021-26068-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 06/22/2021] [Accepted: 09/14/2021] [Indexed: 11/24/2022] Open
Abstract
When the transition temperature of a continuous phase transition is tuned to absolute zero, new ordered phases and physical behaviour emerge in the vicinity of the resulting quantum critical point. Sr3Ru2O7 can be tuned through quantum criticality with magnetic field at low temperature. Near its critical field Bc it displays the hallmark T-linear resistivity and a \documentclass[12pt]{minimal}
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\begin{document}$$T\,{{{{{{\mathrm{log}}}}}}}\,(1/T)$$\end{document}Tlog(1/T) electronic heat capacity behaviour of strange metals. However, these behaviours have not been related to any critical fluctuations. Here we use inelastic neutron scattering to reveal the presence of collective spin fluctuations whose relaxation time and strength show a nearly singular variation with magnetic field as Bc is approached. The large increase in the electronic heat capacity and entropy near Bc can be understood quantitatively in terms of the scattering of conduction electrons by these spin-fluctuations. On entering the spin-density-wave ordered phase present near Bc, the fluctuations become stronger suggesting that the order is stabilised through an “order-by-disorder” mechanism. Sr3Ru2O7 exhibits a quantum critical point tunable by magnetic field and has been widely used in the study of criticality. Here, by using inelastic neutron scattering, the authors measure collective magnetic excitations near the quantum critical point and relate them to thermodynamic properties and spin density wave order.
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Affiliation(s)
- C Lester
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Ave., Bristol, BS8 1TL, UK
| | - S Ramos
- School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
| | - R S Perry
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK
| | - T P Croft
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Ave., Bristol, BS8 1TL, UK
| | - M Laver
- School of Physics and Astronomy, University of Birmingham, Birmingham, BT15 2TT, UK
| | - R I Bewley
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - T Guidi
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - A Hiess
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble, France.,European Spallation Source ERIC, P.O. Box 176, 22100, Lund, Sweden
| | - A Wildes
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble, France
| | - E M Forgan
- School of Physics and Astronomy, University of Birmingham, Birmingham, BT15 2TT, UK
| | - S M Hayden
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Ave., Bristol, BS8 1TL, UK.
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Donnerer C, Rahn MC, Schierle E, Perry RS, Veiga LSI, Nisbet G, Collins SP, Prabhakaran D, Boothroyd AT, McMorrow DF. Selective probing of magnetic order on Tb and Ir sites in stuffed Tb 2Ir 2O 7 using resonant x-ray scattering. J Phys Condens Matter 2019; 31:344001. [PMID: 31096195 DOI: 10.1088/1361-648x/ab2217] [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: 06/09/2023]
Abstract
We study the magnetic structure of the 'stuffed' (Tb-rich) pyrochlore iridate Tb2+x Ir2-x O7-y (x ∼ 0.18), using resonant elastic x-ray scattering (REXS). In order to disentangle contributions from Tb and Ir magnetic sublattices, experiments were performed at the Ir L 3 and Tb M 5 edges, which provide selective sensitivity to Ir 5d and Tb 4f magnetic moments, respectively. At the Ir L 3 edge, we found the onset of long-range [Formula: see text] magnetic order below [Formula: see text] K, consistent with the expected signal of all-in all-out (AIAO) magnetic order. Using a single-ion model to calculate REXS cross-sections, we estimate an ordered magnetic moment of [Formula: see text] at 5 K. At the Tb M 5 edge, long-range [Formula: see text] magnetic order appeared below ∼[Formula: see text] K, also consistent with an AIAO magnetic structure on the Tb site. Additional insight into the magnetism of the Tb sublattice is gleaned from measurements at the M 5 edge in applied magnetic fields up to 6 T, which is found to completely suppress the Tb AIAO magnetic order. In zero applied field, the observed gradual onset of the Tb sublattice magnetisation with temperature suggests that it is induced by the magnetic order on the Ir site. The persistence of AIAO magnetic order, despite the greatly reduced ordering temperature and moment size compared to stoichiometric Tb2Ir2O7, for which [Formula: see text] K and [Formula: see text], indicates that stuffing could be a viable means of tuning the strength of electronic correlations, thereby potentially offering a new strategy to achieve topologically non-trivial band crossings in pyrochlore iridates.
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Affiliation(s)
- C Donnerer
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
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Vale JG, Boseggia S, Walker HC, Springell RS, Hunter EC, Perry RS, Collins SP, McMorrow DF. Critical fluctuations in the spin-orbit Mott insulator Sr 3Ir 2O 7. J Phys Condens Matter 2019; 31:185803. [PMID: 30721882 DOI: 10.1088/1361-648x/ab0471] [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: 06/09/2023]
Abstract
X-ray magnetic critical scattering measurements and specific heat measurements were performed on the perovskite iridate [Formula: see text]. We find that the magnetic interactions close to the Néel temperature [Formula: see text] are three-dimensional. This contrasts with previous studies which suggest two-dimensional behaviour like Sr2IrO4. Violation of the Harris criterion ([Formula: see text]) means that weak disorder becomes relevant. This leads a rounding of the antiferromagnetic phase transition at [Formula: see text], and modifies the critical exponents relative to the clean system. Specifically, we determine that the critical behaviour of [Formula: see text] is representative of the diluted 3D Ising universality class.
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Affiliation(s)
- J G Vale
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London (UCL), Gower Street, London, WC1E 6BT, United Kingdom. Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015, Switzerland
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Tokiwa Y, Mchalwat M, Perry RS, Gegenwart P. Multiple Metamagnetic Quantum Criticality in Sr_{3}Ru_{2}O_{7}. Phys Rev Lett 2016; 116:226402. [PMID: 27314732 DOI: 10.1103/physrevlett.116.226402] [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: 02/23/2016] [Indexed: 06/06/2023]
Abstract
Bilayer strontium ruthenate Sr_{3}Ru_{2}O_{7} displays pronounced non-Fermi liquid behavior at magnetic fields around 8 T, applied perpendicular to the ruthenate planes, which previously has been associated with an itinerant metamagnetic quantum critical end point (QCEP). We focus on the magnetic Grüneisen parameter Γ_{H}, which is the most direct probe to characterize field-induced quantum criticality. We confirm quantum critical scaling due to a putative two-dimensional QCEP near 7.845(5) T, which is masked by two ordered phases A and B, identified previously by neutron scattering. In addition, we find evidence for a QCEP at 7.53(2) T and determine the quantum critical regimes of both instabilities and the effect of their superposition.
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Affiliation(s)
- Y Tokiwa
- I. Physikalisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - M Mchalwat
- I. Physikalisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - R S Perry
- London Centre for Nanotechnology, Faculty of Maths & Physical Sciences, University College London, London-WC1E 6BT, United Kingdom
| | - P Gegenwart
- I. Physikalisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
- Experimentalphysik VI, Center for Electronic Correlations and Magnetism, Augsburg University, 86159 Augsburg, Germany
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de la Torre A, McKeown Walker S, Bruno FY, Riccó S, Wang Z, Gutierrez Lezama I, Scheerer G, Giriat G, Jaccard D, Berthod C, Kim TK, Hoesch M, Hunter EC, Perry RS, Tamai A, Baumberger F. Collapse of the Mott Gap and Emergence of a Nodal Liquid in Lightly Doped Sr(2)IrO(4). Phys Rev Lett 2015; 115:176402. [PMID: 26551128 DOI: 10.1103/physrevlett.115.176402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 06/05/2023]
Abstract
We report angle resolved photoemission experiments on the electron doped Heisenberg antiferromagnet (Sr(1-x)La(x))(2)IrO(4). For a doping level of x=0.05, we find an unusual metallic state with coherent nodal excitations and an antinodal pseudogap bearing strong similarities with underdoped cuprates. This state emerges from a rapid collapse of the Mott gap with doping resulting in a large underlying Fermi surface that is backfolded by a (π,π) reciprocal lattice vector which we attribute to the intrinsic structural distortion of Sr(2)IrO(4).
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Affiliation(s)
- A de la Torre
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S McKeown Walker
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - F Y Bruno
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S Riccó
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Z Wang
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - I Gutierrez Lezama
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - G Scheerer
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - G Giriat
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - D Jaccard
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - C Berthod
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - E C Hunter
- School of Physics and Astronomy, The University of Edinburgh, James Clerk Maxwell Building, Mayfield Road, Edinburgh EH9 2TT, United Kingdom
| | - R S Perry
- London Centre for Nanotechnology and UCL Centre for Materials Discovery, University College London, London WC1E 6BT, United Kingdom
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife KY16 9SS, United Kingdom
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Lester C, Ramos S, Perry RS, Croft TP, Bewley RI, Guidi T, Manuel P, Khalyavin DD, Forgan EM, Hayden SM. Field-tunable spin-density-wave phases in Sr3Ru2O7. Nat Mater 2015; 14:373-378. [PMID: 25581627 DOI: 10.1038/nmat4181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 11/21/2014] [Indexed: 06/04/2023]
Abstract
The conduction electrons in a metal experience competing interactions with each other and the atomic nuclei. This competition can lead to many types of magnetic order in metals. For example, in chromium the electrons order to form a spin-density-wave (SDW) antiferromagnetic state. A magnetic field may be used to perturb or tune materials with delicately balanced electronic interactions. Here, we show that the application of a magnetic field can induce SDW magnetic order in a quasi-2D metamagnetic metal, where none exists in the absence of the field. We use magnetic neutron scattering to show that the application of a large (B ≈ 8 T) magnetic field to the perovskite metal Sr3Ru2O7 (refs 3-7) can be used to tune the material through two magnetically ordered SDW states. The ordered states exist over relatively small ranges in field (≲0.4 T), suggesting that their origin is due to a new mechanism related to the electronic fine structure near the Fermi energy, possibly combined with the stabilizing effect of magnetic fluctuations. The magnetic field direction is shown to control the SDW domain populations, which naturally explains the strong resistivity anisotropy or 'electronic nematic' behaviour observed in this material.
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Affiliation(s)
- C Lester
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK
| | - S Ramos
- School of Physical Sciences, University of Kent, Canterbury CT2 7NH, UK
| | - R S Perry
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - T P Croft
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK
| | - R I Bewley
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK
| | - T Guidi
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK
| | - P Manuel
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK
| | - D D Khalyavin
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK
| | - E M Forgan
- School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK
| | - S M Hayden
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK
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de la Torre A, Hunter EC, Subedi A, McKeown Walker S, Tamai A, Kim TK, Hoesch M, Perry RS, Georges A, Baumberger F. Coherent quasiparticles with a small fermi surface in lightly doped Sr(3)Ir(2)O(7). Phys Rev Lett 2014; 113:256402. [PMID: 25554897 DOI: 10.1103/physrevlett.113.256402] [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: 09/24/2014] [Indexed: 06/04/2023]
Abstract
We characterize the electron doping evolution of (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7} by means of angle-resolved photoemission. Concomitant with the metal insulator transition around x≈0.05 we find the emergence of coherent quasiparticle states forming a closed small Fermi surface of volume 3x/2, where x is the independently measured La concentration. The quasiparticle weight Z remains large along the entire Fermi surface, consistent with the moderate renormalization of the low-energy dispersion, and no pseudogap is observed. This indicates a conventional, weakly correlated Fermi liquid state with a momentum independent residue Z≈0.5 in lightly doped Sr_{3}Ir_{2}O_{7}.
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Affiliation(s)
- A de la Torre
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - E C Hunter
- School of Physics and Astronomy, The University of Edinburgh, James Clerk Maxwell Building, Mayfield Road, Edinburgh EH9 2TT, United Kingdom
| | - A Subedi
- Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France
| | - S McKeown Walker
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - R S Perry
- London Centre for Nanotechnology and UCL Centre for Materials Discovery, University College London, London WC1E 6BT, United Kingdom
| | - A Georges
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland and Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France and Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland and Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, United Kingdom
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Mena M, Perry RS, Perring TG, Le MD, Guerrero S, Storni M, Adroja DT, Rüegg C, McMorrow DF. Spin-wave spectrum of the quantum ferromagnet on the pyrochlore lattice Lu2V2O7. Phys Rev Lett 2014; 113:047202. [PMID: 25105649 DOI: 10.1103/physrevlett.113.047202] [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: 12/14/2013] [Indexed: 06/03/2023]
Abstract
Neutron inelastic scattering has been used to probe the spin dynamics of the quantum (S=1/2) ferromagnet on the pyrochlore lattice Lu(2)V(2)O(7). Well-defined spin waves are observed at all energies and wave vectors, allowing us to determine the parameters of the Hamiltonian of the system. The data are found to be in excellent overall agreement with a minimal model that includes a nearest-neighbor Heisenberg exchange J = 8.22(2) meV and a Dzyaloshinskii-Moriya interaction (DMI) D = 1.5(1) meV. The large DMI term revealed by our study is broadly consistent with the model originally used to explain the magnon Hall effect in this compound [Onose et al., Science 329, 297 (2010) and Ideue et al., Phys. Rev. B 85, 134411 (2012)]. However, our ratio of D/J = 0.18(1) is roughly half of their value, and is much larger than those found in other theoretical studies [Xiang et al., Phys. Rev. B 83, 174402 (2011) and Mook et al., Phys. Rev. B 89,134409 (2014)].
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Affiliation(s)
- M Mena
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom and Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - R S Perry
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom and Centre for Science at Extreme Conditions, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, Scotland
| | - T G Perring
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom and ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - M D Le
- Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany
| | - S Guerrero
- Condensed Matter Theory, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - M Storni
- Condensed Matter Theory, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - D T Adroja
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - Ch Rüegg
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland and DPMC-MaNEP, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - D F McMorrow
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
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12
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Boseggia S, Walker HC, Vale J, Springell R, Feng Z, Perry RS, Moretti Sala M, Rønnow HM, Collins SP, McMorrow DF. Locking of iridium magnetic moments to the correlated rotation of oxygen octahedra in Sr₂IrO₄ revealed by x-ray resonant scattering. J Phys Condens Matter 2013; 25:422202. [PMID: 24067396 DOI: 10.1088/0953-8984/25/42/422202] [Citation(s) in RCA: 6] [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] [Indexed: 06/02/2023]
Abstract
Sr2IrO4 is a prototype of the class of Mott insulators in the strong spin-orbit interaction (SOI) limit described by a Jeff = 1/2 ground state. In Sr2IrO4, the strong SOI is predicted to manifest itself in the locking of the canting of the magnetic moments to the correlated rotation by 11.8(1)° of the oxygen octahedra that characterizes its distorted layered perovskite structure. Using x-ray resonant scattering at the Ir L3 edge we have measured accurately the intensities of Bragg peaks arising from different components of the magnetic structure. From a careful comparison of integrated intensities of peaks due to basal-plane antiferromagnetism, with those due to b-axis ferromagnetism, we deduce a canting of the magnetic moments of 12.2(8)°. We thus confirm that in Sr2IrO4 the magnetic moments rigidly follow the rotation of the oxygen octahedra, indicating that, even in the presence of significant non-cubic structural distortions, it is a close realization of the Jeff = 1/2 state.
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Affiliation(s)
- S Boseggia
- London Centre for Nanotechnology and Department of Physics and Astronomy,University College London, London WC1E 6BT, UK. Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
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13
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Boseggia S, Springell R, Walker HC, Rønnow HM, Rüegg C, Okabe H, Isobe M, Perry RS, Collins SP, McMorrow DF. Robustness of basal-plane antiferromagnetic order and the J(eff)=1/2 state in single-layer iridate spin-orbit Mott insulators. Phys Rev Lett 2013; 110:117207. [PMID: 25166574 DOI: 10.1103/physrevlett.110.117207] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Indexed: 06/03/2023]
Abstract
The magnetic structure and electronic ground state of the layered perovskite Ba(2)IrO(4) have been investigated using x-ray resonant magnetic scattering. Our results are compared with those for Sr(2)IrO(4), for which we provide supplementary data on its magnetic structure. We find that the dominant, long-range antiferromagnetic order is remarkably similar in the two compounds and that the electronic ground state in Ba(2)IrO(4), deduced from an investigation of the x-ray resonant magnetic scattering L(3)/L(2) intensity ratio, is consistent with a J(eff)=1/2 description. The robustness of these two key electronic properties to the considerable structural differences between the Ba and Sr analogues is discussed in terms of the enhanced role of the spin-orbit interaction in 5d transition metal oxides.
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Affiliation(s)
- S Boseggia
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom and Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - R Springell
- Royal Commission for the Exhibition of 1851 Research Fellow, Interface Analysis Centre, University of Bristol, Bristol BS2 8BS, United Kingdom
| | - H C Walker
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - H M Rønnow
- Laboratory for Quantum Magnetism, ICMP, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ch Rüegg
- Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and DPMC-MaNEP, University of Geneva, CH-1211 Geneva, Switzerland
| | - H Okabe
- National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - M Isobe
- National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - R S Perry
- Scottish Universities Physics Alliance, School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom
| | - S P Collins
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - D F McMorrow
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
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14
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Abstract
Many exotic compounds, such as cuprate superconductors and heavy fermion materials, exhibit a linear in temperature (T) resistivity, the origin of which is not well understood. We found that the resistivity of the quantum critical metal Sr(3)Ru(2)O(7) is also T-linear at the critical magnetic field of 7.9 T. Using the precise existing data for the Fermi surface topography and quasiparticle velocities of Sr(3)Ru(2)O(7), we show that in the region of the T-linear resistivity, the scattering rate per kelvin is well approximated by the ratio of the Boltzmann constant to the Planck constant divided by 2π. Extending the analysis to a number of other materials reveals similar results in the T-linear region, in spite of large differences in the microscopic origins of the scattering.
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Affiliation(s)
- J A N Bruin
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, UK
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15
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Abstract
The electronic nematic phase of Sr₃Ru₂O₇ is investigated by high-resolution in-plane thermal expansion measurements in magnetic fields close to 8 T applied at various angles Θ off the c axis. At Θ < 10° we observe a very small (10⁻⁷) lattice distortion which breaks the fourfold in-plane symmetry, resulting in nematic domains with interchanged a and b axis. At Θ ≳ 10° the domains are almost fully aligned and thermal expansion indicates an area-preserving lattice distortion of order 2 × 10⁻⁶ which is likely related to orbital ordering. Since the system is located in the immediate vicinity of a metamagnetic quantum critical end point, the results represent the first observation of a structural relaxation driven by quantum criticality.
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Affiliation(s)
- C Stingl
- I. Physikalisches Institut, Georg-August-Universität Göttingen, D-37077 Göttingen, Germany
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16
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Mercure JF, Goh SK, O'Farrell ECT, Perry RS, Sutherland ML, Rost AW, Grigera SA, Borzi RA, Gegenwart P, Mackenzie AP. Quantum oscillations in the anomalous phase in Sr3Ru2O7. Phys Rev Lett 2009; 103:176401. [PMID: 19905773 DOI: 10.1103/physrevlett.103.176401] [Citation(s) in RCA: 1] [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: 02/02/2009] [Indexed: 05/28/2023]
Abstract
We report measurements of quantum oscillations detected in the putative nematic phase of Sr3Ru2O7. Improvements in sample purity enabled the resolution of small amplitude de Haas-van Alphen (dHvA) oscillations between two first order metamagnetic transitions delimiting the phase. Two distinct frequencies were observed, whose amplitudes follow the normal Lifshitz-Kosevich profile. Variations of the dHvA frequencies are explained in terms of a chemical potential shift produced by reaching a peak in the density of states, and an anomalous field dependence of the oscillatory amplitude provides information on domains.
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Affiliation(s)
- J-F Mercure
- Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, United Kingdom
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17
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Morris DJP, Tennant DA, Grigera SA, Klemke B, Castelnovo C, Moessner R, Czternasty C, Meissner M, Rule KC, Hoffmann JU, Kiefer K, Gerischer S, Slobinsky D, Perry RS. Dirac Strings and Magnetic Monopoles in the Spin Ice Dy
2
Ti
2
O
7. Science 2009; 326:411-4. [DOI: 10.1126/science.1178868] [Citation(s) in RCA: 447] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- D. J. P. Morris
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
| | - D. A. Tennant
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
- Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany
| | - S. A. Grigera
- School of Physics and Astronomy, North Haugh, St. Andrews, Fife KY15 9SS, UK
- Instituto de Física de Líquidos y Sistemas Biológicos, CONICET, UNLP, La Plata, Argentina
| | - B. Klemke
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
- Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany
| | - C. Castelnovo
- Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, UK
| | - R. Moessner
- Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany
| | - C. Czternasty
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
| | - M. Meissner
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
| | - K. C. Rule
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
| | - J.-U. Hoffmann
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
| | - K. Kiefer
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
| | - S. Gerischer
- Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, D-14109 Berlin, Germany
| | - D. Slobinsky
- School of Physics and Astronomy, North Haugh, St. Andrews, Fife KY15 9SS, UK
| | - R. S. Perry
- School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK
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18
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Rost AW, Perry RS, Mercure JF, Mackenzie AP, Grigera SA. Entropy Landscape of Phase Formation Associated with Quantum Criticality in Sr
3
Ru
2
O
7. Science 2009; 325:1360-3. [DOI: 10.1126/science.1176627] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- A. W. Rost
- Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, UK
| | - R. S. Perry
- SUPA, School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK
| | - J.-F. Mercure
- Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, UK
| | - A. P. Mackenzie
- Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, UK
| | - S. A. Grigera
- Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, UK
- Instituto de Física de Líquidos y Sistemas Biológicos, Universidad Nacional de La Plata–Consejo Nacional de Investigaciones Científicas y Técnicas, 1900 La Plata, Argentina
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19
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Tamai A, Allan MP, Mercure JF, Meevasana W, Dunkel R, Lu DH, Perry RS, Mackenzie AP, Singh DJ, Shen ZX, Baumberger F. Fermi surface and van Hove singularities in the itinerant Metamagnet Sr3Ru2O7. Phys Rev Lett 2008; 101:026407. [PMID: 18764208 DOI: 10.1103/physrevlett.101.026407] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Indexed: 05/26/2023]
Abstract
The low-energy electronic structure of the itinerant metamagnet Sr3Ru2O7 is investigated by angle-resolved photoemission and density-functional calculations. We find well-defined quasiparticle bands with resolution-limited linewidths and Fermi velocities up to an order of magnitude lower than in single layer Sr2RuO4. The complete topography, the cyclotron masses, and the orbital character of the Fermi surface are determined, in agreement with bulk sensitive de Haas-van Alphen measurements. An analysis of the dxy band dispersion reveals a complex density of states with van Hove singularities near the Fermi level, a situation which is favorable for magnetic instabilities.
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Affiliation(s)
- A Tamai
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS, United Kingdom.
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20
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Borzi RA, Grigera SA, Farrell J, Perry RS, Lister SJS, Lee SL, Tennant DA, Maeno Y, Mackenzie AP. Formation of a Nematic Fluid at High Fields in Sr3Ru2O7. Science 2006; 315:214-7. [PMID: 17124288 DOI: 10.1126/science.1134796] [Citation(s) in RCA: 376] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In principle, a complex assembly of strongly interacting electrons can self-organize into a wide variety of collective states, but relatively few such states have been identified in practice. We report that, in the close vicinity of a metamagnetic quantum critical point, high-purity strontium ruthenate Sr3Ru2O7 possesses a large magnetoresistive anisotropy, consistent with the existence of an electronic nematic fluid. We discuss a striking phenomenological similarity between our observations and those made in high-purity two-dimensional electron fluids in gallium arsenide devices.
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Affiliation(s)
- R A Borzi
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS, UK.
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21
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Ronning F, Hill RW, Sutherland M, Hawthorn DG, Tanatar MA, Paglione J, Taillefer L, Graf MJ, Perry RS, Maeno Y, Mackenzie AP. Thermal conductivity in the vicinity of the quantum critical end point in Sr3Ru2O7. Phys Rev Lett 2006; 97:067005. [PMID: 17026193 DOI: 10.1103/physrevlett.97.067005] [Citation(s) in RCA: 5] [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: 02/13/2006] [Indexed: 05/12/2023]
Abstract
Thermal conductivity of Sr3Ru2O7 was measured down to 40 mK and at magnetic fields through the quantum critical end point at Hc=7.85 T. A peak in the electrical resistivity as a function of the field was mimicked by the thermal resistivity. In the limit as T-->0 K, we find that the Wiedemann-Franz law is satisfied to within 5% at all fields, implying that there is no breakdown of the electron despite the destruction of the Fermi liquid state at quantum criticality. A significant change in disorder [from rho0(H=0 T)=2.1 to 0.5 microOmega cm] does not influence our conclusions. At finite temperatures, the temperature dependence of the Lorenz number is consistent with ferromagnetic fluctuations causing the non-Fermi liquid behavior as one would expect at a metamagnetic quantum critical end point.
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Affiliation(s)
- F Ronning
- Department of Physics, University of Toronto, Toronto, Ontario, Canada
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22
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Baumberger F, Ingle NJC, Meevasana W, Shen KM, Lu DH, Perry RS, Mackenzie AP, Hussain Z, Singh DJ, Shen ZX. Fermi surface and quasiparticle excitations of Sr2RhO4. Phys Rev Lett 2006; 96:246402. [PMID: 16907260 DOI: 10.1103/physrevlett.96.246402] [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: 12/30/2005] [Indexed: 05/11/2023]
Abstract
The electronic structure of the layered 4d transition metal oxide Sr2RhO4 is investigated by angle resolved photoemission. We find well-defined quasiparticle excitations with a highly anisotropic dispersion, suggesting a quasi-two-dimensional Fermi-liquid-like ground state. Markedly different from the isostructural Sr2RuO4, only two bands with dominant Rh 4dxz,zy character contribute to the Fermi surface. A quantitative analysis of the photoemission quasiparticle band structure is in excellent agreement with bulk data. In contrast, it is found that state-of-the-art density functional calculations in the local density approximation differ significantly from the experimental findings.
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Affiliation(s)
- F Baumberger
- Department of Applied Physics, and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, USA
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23
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Gegenwart P, Weickert F, Garst M, Perry RS, Maeno Y. Metamagnetic quantum criticality in Sr3Ru2O7 studied by thermal expansion. Phys Rev Lett 2006; 96:136402. [PMID: 16712009 DOI: 10.1103/physrevlett.96.136402] [Citation(s) in RCA: 5] [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: 07/15/2005] [Indexed: 05/09/2023]
Abstract
We report low-temperature thermal expansion measurements on the bilayer ruthenate Sr3Ru2O7 as a function of magnetic field applied perpendicular to the ruthenium-oxide planes. The field dependence of the c-axis expansion coefficient indicates the accumulation of entropy close to 8 T, related to an underlying quantum critical point. The latter is masked by two first-order metamagnetic transitions which bound a regime of enhanced entropy. Outside this region the singular thermal expansion behavior is compatible with the predictions of the itinerant theory for a two-dimensional metamagnetic quantum critical end point.
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Affiliation(s)
- P Gegenwart
- Max-Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
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24
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Baumberger F, Ingle NJC, Kikugawa N, Hossain MA, Meevasana W, Perry RS, Shen KM, Lu DH, Damascelli A, Rost A, Mackenzie AP, Hussain Z, Shen ZX. Nested fermi surface and electronic instability in Ca3Ru2O7. Phys Rev Lett 2006; 96:107601. [PMID: 16605788 DOI: 10.1103/physrevlett.96.107601] [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: 07/15/2005] [Indexed: 05/08/2023]
Abstract
High-resolution angular resolved photoemission data reveal well-defined quasiparticle bands of unusually low weight, emerging in line with the metallic phase of Ca(3)Ru(2)O(7) below approximately 30 K . At the bulk structural phase transition temperature of 48 K, we find clear evidence for an electronic instability, gapping large parts of the underlying Fermi surface that appears to be nested. Metallic pockets are found to survive in the small, non-nested sections, constituting a low-temperature Fermi surface with 2 orders of magnitude smaller volume than in all other metallic ruthenates. The Fermi velocities and volumes of these pockets are in agreement with the results of complementary quantum oscillation measurements on the same crystal batches.
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Affiliation(s)
- F Baumberger
- Department of Applied Physics, and Stanford Synchrotron Radiation Laboratory, Stanford University, California 94305, USA
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25
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Kitagawa K, Ishida K, Perry RS, Tayama T, Sakakibara T, Maeno Y. Metamagnetic quantum criticality revealed by 17O-NMR in the itinerant metamagnet Sr3Ru2O7. Phys Rev Lett 2005; 95:127001. [PMID: 16197099 DOI: 10.1103/physrevlett.95.127001] [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: 03/07/2005] [Indexed: 05/04/2023]
Abstract
We have investigated the spin dynamics using 17O-NMR in the bilayered perovskite Sr3Ru2O7, which sits close to a metamagnetic quantum critical point. The nuclear spin-lattice relaxation rate divided by temperature 1/T1T is enhanced on approaching the metamagnetic critical field of approximately 7.9 T, and at the critical field 1/T1T continues to increase and does not show Fermi-liquid behavior down to 0.3 K. The temperature dependence of T1T in this region suggests the critical temperature Theta to be approximately 0 K, which is strong evidence that the spin dynamics possesses a quantum critical character. Comparison between uniform susceptibility and 1/T1T reveals that antiferromagnetic fluctuations instead of two-dimensional ferromagnetic fluctuations dominate the spin fluctuation spectrum at the critical field, which is unexpected for itinerant metamagnetism.
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Affiliation(s)
- K Kitagawa
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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26
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Green AG, Grigera SA, Borzi RA, Mackenzie AP, Perry RS, Simons BD. Phase bifurcation and quantum fluctuations in Sr3Ru2O7. Phys Rev Lett 2005; 95:086402. [PMID: 16196876 DOI: 10.1103/physrevlett.95.086402] [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: 10/19/2004] [Indexed: 05/04/2023]
Abstract
The bilayer ruthenate Sr3Ru2O7 has been cited as a textbook example of itinerant metamagnetic quantum criticality. However, recent studies of the ultrapure system have revealed striking anomalies in magnetism and transport in the vicinity of the quantum critical point. Drawing on fresh experimental data, we show that the complex phase behavior reported here can be fully accommodated within the framework of a simple Landau theory. We discuss the potential physical mechanisms that underpin the phenomenology, and assess the capacity of the ruthenate system to realize quantum tricritial behavior.
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Affiliation(s)
- A G Green
- School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, United Kingdom
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27
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Grigera SA, Gegenwart P, Borzi RA, Weickert F, Schofield AJ, Perry RS, Tayama T, Sakakibara T, Maeno Y, Green AG, Mackenzie AP. Disorder-Sensitive Phase Formation Linked to Metamagnetic Quantum Criticality. Science 2004; 306:1154-7. [PMID: 15539596 DOI: 10.1126/science.1104306] [Citation(s) in RCA: 216] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Condensed systems of strongly interacting electrons are ideal for the study of quantum complexity. It has become possible to promote the formation of new quantum phases by explicitly tuning systems toward special low-temperature quantum critical points. So far, the clearest examples have been appearances of superconductivity near pressure-tuned antiferromagnetic quantum critical points. We present experimental evidence for the formation of a nonsuperconducting phase in the vicinity of a magnetic field-tuned quantum critical point in ultrapure crystals of the ruthenate metal Sr3Ru2O7, and we discuss the possibility that the observed phase is due to a spin-dependent symmetry-breaking Fermi surface distortion.
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Affiliation(s)
- S A Grigera
- School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS, Scotland.
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28
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Borzi RA, Grigera SA, Perry RS, Kikugawa N, Kitagawa K, Maeno Y, Mackenzie AP. de Haas-van Alphen effect across the metamagnetic transition in Sr3Ru2O7. Phys Rev Lett 2004; 92:216403. [PMID: 15245301 DOI: 10.1103/physrevlett.92.216403] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Indexed: 05/24/2023]
Abstract
We report a study of the de Haas-van Alphen (dHvA) effect on the itinerant metamagnet Sr3Ru2O7. Extremely high sample purity allows the observation of dHvA oscillations both above and below the metamagnetic transition field of 7.9 T. The quasiparticle masses are fairly large away from the transition, and are enhanced by up to an extra factor of 3 as the transition is approached, but the Fermi surface topography change is quite small. The results are qualitatively consistent with a field-induced Stoner transition in which the mass enhancement is the result of critical fluctuations.
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Affiliation(s)
- R A Borzi
- School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
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29
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Perry RS, Kitagawa K, Grigera SA, Borzi RA, Mackenzie AP, Ishida K, Maeno Y. Multiple first-order metamagnetic transitions and quantum oscillations in ultrapure Sr3Ru2O7. Phys Rev Lett 2004; 92:166602. [PMID: 15169251 DOI: 10.1103/physrevlett.92.166602] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Indexed: 05/24/2023]
Abstract
We present measurements on ultraclean single crystals of the bilayered ruthenate metal Sr3Ru2O7, which has a magnetic-field-tuned quantum critical point. Quantum oscillations of differing frequencies can be seen in the resistivity both below and above its metamagnetic transition. This frequency shift corresponds to a small change in the Fermi surface volume that is qualitatively consistent with the small moment change in the magnetization across the metamagnetic transition. Very near the metamagnetic field, unusual behavior is seen. There is a strong enhancement of the resistivity in a narrow field window, with a minimum in the resistivity as a function of temperature below 1 K that becomes more pronounced as the disorder level decreases. The region of anomalous behavior is bounded at low temperatures by two first-order phase transitions. The implications of the results are discussed.
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Affiliation(s)
- R S Perry
- Kyoto University International Innovation Center, Kyoto 606-8501, Japan
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Capogna L, Mackenzie AP, Perry RS, Grigera SA, Galvin LM, Raychaudhuri P, Schofield AJ, Alexander CS, Cao G, Julian SR, Maeno Y. Sensitivity to disorder of the metallic state in the ruthenates. Phys Rev Lett 2002; 88:076602. [PMID: 11863926 DOI: 10.1103/physrevlett.88.076602] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2001] [Indexed: 05/23/2023]
Abstract
We report the results of transport measurements on SrRuO3, Sr3Ru2O7, and CaRuO3. In SrRuO3 and Sr3Ru2O7, our findings are consistent with the predictions of Fermi liquid theory, in contrast to previous reports based on samples with much shorter mean free paths. In CaRuO3, however, a T1.5 power law is seen in the resistivity in the high purity samples studied here. Our work gives concrete evidence that even the metallic state of the ruthenates is highly sensitive to disorder.
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Affiliation(s)
- L Capogna
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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Grigera SA, Perry RS, Schofield AJ, Chiao M, Julian SR, Lonzarich GG, Ikeda SI, Maeno Y, Millis AJ, Mackenzie AP. Magnetic field-tuned quantum criticality in the metallic ruthenate Sr3Ru2O7. Science 2001; 294:329-32. [PMID: 11598292 DOI: 10.1126/science.1063539] [Citation(s) in RCA: 467] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The concept of quantum criticality is proving to be central to attempts to understand the physics of strongly correlated electrons. Here, we argue that observations on the itinerant metamagnet Sr3Ru2O7 represent good evidence for a new class of quantum critical point, arising when the critical end point terminating a line of first-order transitions is depressed toward zero temperature. This is of interest both in its own right and because of the convenience of having a quantum critical point for which the tuning parameter is the magnetic field. The relationship between the resultant critical fluctuations and novel behavior very near the critical field is discussed.
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Affiliation(s)
- S A Grigera
- School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS, UK.
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Perry RS, Galvin LM, Grigera SA, Capogna L, Schofield AJ, Mackenzie AP, Chiao M, Julian SR, Ikeda SI, Nakatsuji S, Maeno Y, Pfleiderer C. Metamagnetism and critical fluctuations in high quality single crystals of the bilayer ruthenate Sr3Ru2O7. Phys Rev Lett 2001; 86:2661-2664. [PMID: 11290005 DOI: 10.1103/physrevlett.86.2661] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2000] [Indexed: 05/23/2023]
Abstract
We report the results of low temperature transport, specific heat, and magnetization measurements on high quality single crystals of the bilayer perovskite Sr3Ru2O7, which is a close relative of the unconventional superconductor Sr2RuO4. Metamagnetism is observed, and transport and thermodynamic evidence for associated critical fluctuations is presented. These relatively unusual fluctuations might be pictured as variations in the Fermi surface topography itself.
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Affiliation(s)
- R S Perry
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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Perry RS, Illsley SS. Basic cardiac electrophysiology and mechanisms of antiarrhythmic agents. Am J Hosp Pharm 1986; 43:957-74. [PMID: 2871752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Basic cardiac electrophysiology and how it applies to antiarrhythmic drug therapy are reviewed. Normal impulse propagation through the heart proceeds in sequence from the sinoatrial (SA) node, through the atrial specialized conducting system, the atrioventricular (AV) node, the His-Pur-kinje system, and into the ventricles. The cardiac cell maintains a resting membrane potential until an electrical stimulus depolarizes the cell and generates an action potential. The action potential is composed of five phases that represent the changing ionic fluxes and membrane potentials of the cardiac cell. The heart contains two types of cardiac conducting fibers. The fast- and slow-current action potentials generated by these fiber types exhibit distinctly different electrophysiologic properties. Cardiac arrhythmias generally result from an abnormality in the rate, rhythm, or conduction of an electrical impulse in the heart. They may be described as disturbances in normal impulse initiation (automaticity), impulse conduction, or both. Various portions of the conduction system are under the control of the autonomic nervous system, which depends on the balance between the activity of the parasympathetic and sympathetic nervous systems. Intracellular and extracellular concentrations of potassium, calcium, and magnesium have important effects on the electrophysiology of the heart. These changes can be critical in the production of various arrhythmias or may affect the efficacy or toxicity of various antiarrhythmic agents. The electrophysiology of quinidine, procainamide, disopyramide, lidocaine, tocainide, phenytoin, flecainide, amiodarone, and bretylium tosylate is discussed to detail the relationship between drug action and antiarrhythmic efficacy. The electrophysiologic effects of beta-blocking agents and calcium-channel antagonists are also presented. This basic primer on cardiac electrophysiology should provide the practitioner with an improved understanding of the effects, indications, and limitations of antiarrhythmic drugs.
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Perry RS. Contemporary recommendations for evaluating and treating hyperlipidemia. Clin Pharm 1986; 5:113-27. [PMID: 3514084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The biochemistry, etiology, and evaluation of hyperlipidemia and its management, including dietary and drug therapies, are discussed. Strong evidence supports the role of increased cholesterol concentrations as an independent risk factor for coronary artery disease (CAD); however, evidence that elevated triglyceride concentrations are also an independent risk factor remains questionable. The cornerstone of the laboratory diagnosis of hyperlipidemia involves repeated measurement of serum or plasma cholesterol and triglyceride concentrations. The goals of therapy should be to reduce cholesterol or triglyceride concentrations or both to below the 75th percentile, modify co-existing risk factors, individualize the treatment, and minimize any adverse effects. Specific interventions must be determined on the basis of patient age, gender, etiology of hyperlipidemia, presence of other risk factors, and degree of lipid abnormality. The majority of patients may be managed with dietary therapy alone. The three-phase diet developed by the American Heart Association emphasizes a gradual reduction in cholesterol and fats with the substitution of polyunsaturated for saturated fats. Patients at risk for CAD with sustained elevations in plasma cholesterol concentrations above the 95th percentile or a triglyceride concentration above 500 mg/dL after an adequate dietary trial should be considered for drug therapy. The effects of cholestyramine and colestipol hydrochloride, niacin, dextrothyroxine, clofibrate, neomycin sulfate, probucol, gemfibrozil, and mevinolin and compactin on lipids and lipoproteins are reviewed. Hyperlipidemia should be managed systematically using information about the association between increased lipid concentrations and CAD, patient risk factors, and limitations of both diet and drug therapy.
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Perry RS. Salt substitute as potassium replacement in hypertensive patients. Clin Pharm 1986; 5:156-9. [PMID: 3956125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Perry RS. Recognition and management of acute suppurative parotitis. Clin Pharm 1985; 4:566-71. [PMID: 4053524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Acute suppurative parotitis (ASP) is a rare infectious process occurring after surgery or in debilitated patients. This case describes a 41-year-old man who was hospitalized initially for acute bacterial endocarditis. Late in the hospital course his recovery was complicated by the development of ASP. Subsequent cultures of blood and parotid-fluid samples grew Pseudomonas aeruginosa. Despite early empiric antibiotic therapy followed by more specific therapy with an aminoglycoside, the patient continued to experience severe pain, swelling, and facial-nerve palsy. Surgical incision and drainage of the parotid gland was accomplished on the ninth day after onset of ASP, and the patient experienced a rapid resolution of the disease process. Acute suppurative parotitis was originally attributed to infection with gram-positive organisms, primarily Staphylococcus aureus and Streptococcus species. More recently, reports of ASP caused by gram-negative and anaerobic bacteria have been published. This review describes the etiology, pathogenesis, microbiology, and clinical features of ASP. Nonpharmacologic, pharmacologic, and surgical management of the disease is discussed. Although ASP is a rare occurrence in the hospital setting, early recognition and appropriate management are important in avoiding serious morbidity and mortality.
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Perry RS, Gallagher J. Management of maldigestion associated with pancreatic insufficiency. Clin Pharm 1985; 4:161-9. [PMID: 3987214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The etiology, pathophysiology, clinical presentation, dietary management, and drug therapy of maldigestion associated with pancreatic insufficiency are reviewed. Maldigestion can occur in a number of conditions that lead to pancreatic insufficiency but is seen most frequently in patients with alcohol-related chronic pancreatitis or cystic fibrosis. Destruction of pancreatic tissue and obstruction of the ducts that lead into the small intestine prevent pancreatic secretions from reaching the small intestine and result in weight loss, anorexia, abdominal distention, and changes in the appearance and frequency of stools. The goal of dietary intervention in patients with maldigestion is to provide sufficient calories and protein to maintain weight while limiting fat intake to an amount tht the patient can tolerate. Medium-chain triglycerides can be substituted for dietary fat in patients whose symptoms continue despite dietary fat restriction. Drug therapy involves supplementing deficient pancreatic enzymes with pancreatin or pancrelipase. Regimens must be individualized for each patient because of problems with gastric inactivation of orally administered enzymes, lack of standardization of commercially available preparations, and large interpatient variation in response. In selecting an enzyme supplement preparation, the amount of available enzyme activity, dosage form, number of dosage units needed per dose, dosage schedule, and product cost must be considered. When enzyme supplementation alone does not adequately control the symptoms of maldigestion, a histamine H2-receptor antagonist or antacids may be added to the therapeutic regimen. Although complete resolution of the symptoms of maldigestion is difficult to achieve, a regimen of dietary modification and pancreatic-enzyme replacement can improve patients' quality of life.
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Abstract
During summer stratification,Metallogenium personatun was found exclusively in the hypolimnion of Lake Washington where the oxygen tension was below 8 ppm. Numbers of the organism decreased in the lake immediately following turnover in October. Significant concentrations ofMetallogenium microcolonies did not recur until spring, after the lake had stratified. During stratification the distribution of particulate manganese closely followed the distribution ofMetallogenium. EDAX analysis, confirmed by electron microprobe analyses of the encrustation, showed that the primary component was manganese. Iron and some trace elements were also precipitated on the organism but to a lesser degree. In addition, phosphate, the primary substance limiting phytoplankton growth in Lake Washington, was found in the encrustation, indicatingMetallogenium maybe important in limiting algal blooms in the lake. Attempts to growMetallogenium in the laboratory were unsuccessful. This inability, combined with the negative results of thin-sectioning and acridine orange staining ofMetallogenium microcolonies, suggests that the microcolonial structures seen in Lake Washington are not a living form of an organism.
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Affiliation(s)
- E Gregory
- Department of Microbiology and Immunology, and Department of Geological Sciences, University of Washington, 98195, Seattle, Washington
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Abstract
1. The differential sensitivity of saphenous nerve fibres in the cat to block by procaine HCl was re-examined by recording identifiable unit action potentials from small nerve filaments.2. Small myelinated axons were blocked more quickly than large myelinated axons, but this differential effect could not be accounted for by differences in anaesthetic concentration requirements.3. The onset of block in non-myelinated axons was slower than or equal to that of small myelinated axons depending on anaesthetic concentration.4. Absolute differential block of non-myelinated and small myelinated axons was obtained by limiting the length of axons exposed to procaine to 2 mm.5. Differential rates of blocking among myelinated axons appear to depend on differences in the length of axons that must be exposed to blocking concentrations of procaine and to arise from the irregular distribution of such concentrations within an exposed nerve.
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Downes H, Perry RS, Ostlund RE, Karler R. A study of the excitatory effects of barbiturates. J Pharmacol Exp Ther 1970; 175:692-9. [PMID: 5489924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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