1
|
Gozlinski T, Henn M, Wolf T, Le Tacon M, Schmalian J, Wulfhekel W. Bosonic excitation spectra of superconductingBi2Sr2CaCu2O8+δandYBa2Cu3O6+xextracted from scanning tunneling spectra. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:175601. [PMID: 38194720 DOI: 10.1088/1361-648x/ad1ca8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/09/2024] [Indexed: 01/11/2024]
Abstract
A detailed interpretation of scanning tunneling spectra obtained on unconventional superconductors enables one to gain information on the pairing boson. Decisive for this approach are inelastic tunneling events. Due to the lack of momentum conservation in tunneling from or to the sharp tip, those are enhanced in the geometry of a scanning tunneling microscope compared to planar tunnel junctions. This work extends the method of obtaining the bosonic excitation spectrum by deconvolution from tunneling spectra to nodald-wave superconductors. In particular, scanning tunneling spectra of slightly underdopedBi2Sr2CaCu2O8+δwith aTcof 82 K and optimally dopedYBa2Cu3O6+xwith aTcof 92 K reveal a resonance mode in their bosonic excitation spectrum atΩres≈63 meVandΩres≈61 meVrespectively. In both cases, the overall shape of the bosonic excitation spectrum is indicative of predominant spin scattering with a resonant mode atΩres<2Δand overdamped spin fluctuations for energies larger than 2Δ. To perform the deconvolution of the experimental data, we implemented an efficient iterative algorithm that significantly enhances the reliability of our analysis.
Collapse
Affiliation(s)
- Thomas Gozlinski
- Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Mirjam Henn
- Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Thomas Wolf
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Matthieu Le Tacon
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Jörg Schmalian
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
- Institute for Theory of Condensed Matter, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Wulf Wulfhekel
- Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| |
Collapse
|
2
|
Silkin VM, Drechsler SL, Efremov DV. Unusual Low-Energy Collective Charge Excitations in High- Tc Cuprate Superconductors. J Phys Chem Lett 2023; 14:8060-8068. [PMID: 37655950 PMCID: PMC10510710 DOI: 10.1021/acs.jpclett.3c01871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 08/14/2023] [Indexed: 09/02/2023]
Abstract
Despite decades of intensive experimental and theoretical efforts, the physics of cuprate high-temperature superconductors in general, and, in particular, their normal state, is still under debate. Here, we report our investigation of low-energy charge excitations in the normal state. We find that the peculiarities of the electronic band structure at low energies have a profound impact on the nature of the intraband collective modes. It gives rise to a new kind of mode with huge intensity and non-Lorentzian spectral function in addition to well-known collective excitations like conventional plasmons and spin fluctuation. We predict two such modes with maximal spectral weight in the nodal and antinodal directions. Additionally, we found a long-living quasi-one-dimensional plasmon becoming an intense soft mode over an extended momentum range along the antinodal direction. These modes might explain some of the resonant inelastic X-ray scattering spectroscopy data.
Collapse
Affiliation(s)
- Vyacheslav M. Silkin
- Donostia
International Physics Center (DIPC), 20018 San Sebastián/Donostia, Basque Country, Spain
- Departamento
de Polímeros y Materiales Avanzados: Física,
Química y Tecnología, Facultad de Ciencias
Químicas, Universidad del País
Vasco UPV/EHU, 20080 San Sebastián/Donostia, Basque Country, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
| | - Stefan-Ludwig Drechsler
- Leibniz
Institute for Solid State and Materials Research IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| | - Dmitry V. Efremov
- Leibniz
Institute for Solid State and Materials Research IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
| |
Collapse
|
3
|
Jang H, Song S, Kihara T, Liu Y, Lee SJ, Park SY, Kim M, Kim HD, Coslovich G, Nakata S, Kubota Y, Inoue I, Tamasaku K, Yabashi M, Lee H, Song C, Nojiri H, Keimer B, Kao CC, Lee JS. Characterization of photoinduced normal state through charge density wave in superconducting YBa 2Cu 3O 6.67. SCIENCE ADVANCES 2022; 8:eabk0832. [PMID: 35138893 PMCID: PMC8827649 DOI: 10.1126/sciadv.abk0832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
The normal state of high-Tc cuprates has been considered one of the essential topics in high-temperature superconductivity research. However, compared to the high magnetic field study of it, understanding a photoinduced normal state remains elusive. Here, we explore a photoinduced normal state of YBa2Cu3O6.67 through a charge density wave (CDW) with time-resolved resonant soft x-ray scattering, as well as a high magnetic field x-ray scattering. In the nonequilibrium state where people predict a quenched superconducting state based on the previous optical spectroscopies, we experimentally observed a similar analogy to the competition between superconductivity and CDW shown in the equilibrium state. We further observe that the broken pairing states in the superconducting CuO2 plane via the optical pump lead to nucleation of three-dimensional CDW precursor correlation. Ultimately, these findings provide a critical clue that the characteristics of the photoinduced normal state show a solid resemblance to those under magnetic fields in equilibrium conditions.
Collapse
Affiliation(s)
- Hoyoung Jang
- PAL-XFEL, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
- Photon Science Center, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Sanghoon Song
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Takumi Kihara
- Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan
| | - Yijin Liu
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Sang-Jun Lee
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Sang-Youn Park
- PAL-XFEL, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Minseok Kim
- PAL-XFEL, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Hyeong-Do Kim
- PAL-XFEL, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Giacomo Coslovich
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Suguru Nakata
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany
| | - Yuya Kubota
- RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo, 679-5198, Japan
| | - Ichiro Inoue
- RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan
| | | | - Makina Yabashi
- RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo, 679-5198, Japan
| | - Heemin Lee
- Departments of Physics, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Changyong Song
- Photon Science Center, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
- Departments of Physics, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Hiroyuki Nojiri
- Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan
| | - Bernhard Keimer
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany
| | - Chi-Chang Kao
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Jun-Sik Lee
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| |
Collapse
|
4
|
Kloss T, Montiel X, de Carvalho VS, Freire H, Pépin C. Charge orders, magnetism and pairings in the cuprate superconductors. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:084507. [PMID: 27427401 DOI: 10.1088/0034-4885/79/8/084507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We review the recent developments in the field of cuprate superconductors with special focus on the recently observed charge order in the underdoped compounds. We introduce new theoretical developments following the study of the antiferromagnetic quantum critical point in two dimensions, in which preemptive orders in both charge and superconducting (SC) sectors emerge, that are in turn related by an SU(2) symmetry. We consider the implications of this proliferation of orders in the underdoped region, and provide a study of the type of fluctuations which characterize the SU(2) symmetry. We identify an intermediate energy scale where the SC fluctuations are dominant and argue that they are unstable towards the formation of a resonant excitonic state at the pseudogap temperature T (*). We discuss the implications of this scenario for a few key experiments.
Collapse
Affiliation(s)
- T Kloss
- IPhT, L'Orme des Merisiers, CEA-Saclay, 91191 Gif-sur-Yvette, France
| | | | | | | | | |
Collapse
|
5
|
Gallais Y, Paul I, Chauvière L, Schmalian J. Nematic Resonance in the Raman Response of Iron-Based Superconductors. PHYSICAL REVIEW LETTERS 2016; 116:017001. [PMID: 26799039 DOI: 10.1103/physrevlett.116.017001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 06/05/2023]
Abstract
In a fully gapped superconductor the electronic Raman response has a pair-breaking peak at twice the superconducting gap Δ, if the Bogoliubov excitations are uncorrelated. Motivated by the iron based superconductors, we study how this peak is modified if the superconducting phase hosts a nematic-structural quantum critical point. We show that, upon approaching this point by tuning, e.g., doping, the growth of nematic correlations between the quasiparticles transforms the pair-breaking peak into a nematic resonance. The mode energy is below 2Δ, and stays finite at the quantum critical point, where its spectral weight is sharply enhanced. The latter is consistent with recent experiments on electron-doped iron based superconductors and provides direct evidence of nematic correlations in their superconducting phases.
Collapse
Affiliation(s)
- Yann Gallais
- Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France
| | - Indranil Paul
- Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France
| | - Ludivine Chauvière
- Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet, 75205 Paris Cedex 13, France
| | - Jörg Schmalian
- Institute for Theory of Condensed Matter, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute for Solid State Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| |
Collapse
|
6
|
Zhao D, Ma FX, Zhang RJ, Li FF, Zhang L, Yang J, Fan YC, Xin X. Structure modulation, band structure, density of states and luminescent properties of columbite-type ZnNb2O6. CrystEngComm 2016. [DOI: 10.1039/c5ce01828e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study reports the four-dimensional commensurately modulated structure of ZnNb2O6 using superspace formalism for aperiodic structures considering the modulation vector, q = 1/3 b*.
Collapse
Affiliation(s)
- Dan Zhao
- Department of Physics and Chemistry
- Henan Polytechnic University
- Jiaozuo 454000, China
| | - Fa-Xue Ma
- Department of Physics and Chemistry
- Henan Polytechnic University
- Jiaozuo 454000, China
| | - Rui-Juan Zhang
- Department of Physics and Chemistry
- Henan Polytechnic University
- Jiaozuo 454000, China
| | - Fei-Fei Li
- Department of Physics and Chemistry
- Henan Polytechnic University
- Jiaozuo 454000, China
| | - Lei Zhang
- Department of Physics and Chemistry
- Henan Polytechnic University
- Jiaozuo 454000, China
| | - Juan Yang
- Department of Physics and Chemistry
- Henan Polytechnic University
- Jiaozuo 454000, China
| | - Yun-Chang Fan
- Department of Physics and Chemistry
- Henan Polytechnic University
- Jiaozuo 454000, China
| | - Xia Xin
- National Engineering Technology Research Center For Colloidal Materials
- Shandong University
- Jinan 250100, China
| |
Collapse
|
7
|
Comin R, Sutarto R, da Silva Neto EH, Chauviere L, Liang R, Hardy WN, Bonn DA, He F, Sawatzky GA, Damascelli A. Superconductivity. Broken translational and rotational symmetry via charge stripe order in underdoped YBa₂Cu₃O(6+y). Science 2015; 347:1335-9. [PMID: 25792325 DOI: 10.1126/science.1258399] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
After the discovery of stripelike order in lanthanum-based copper oxide superconductors, charge-ordering instabilities were observed in all cuprate families. However, it has proven difficult to distinguish between unidirectional (stripes) and bidirectional (checkerboard) charge order in yttrium- and bismuth-based materials. We used resonant x-ray scattering to measure the two-dimensional structure factor in the superconductor YBa2Cu3O(6+y) in reciprocal space. Our data reveal the presence of charge stripe order (i.e., locally unidirectional density waves), which may represent the true microscopic nature of charge modulation in cuprates. At the same time, we find that the well-established competition between charge order and superconductivity is stronger for charge correlations across the stripes than along them, which provides additional evidence for the intrinsic unidirectional nature of the charge order.
Collapse
Affiliation(s)
- R Comin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
| | - R Sutarto
- Canadian Light Source, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - E H da Silva Neto
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada. Quantum Materials Program, Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada. Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | - L Chauviere
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada. Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | - R Liang
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - D A Bonn
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - F He
- Canadian Light Source, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - G A Sawatzky
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - A Damascelli
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
| |
Collapse
|
8
|
Spin excitations of ferronematic order in underdoped cuprate superconductors. Sci Rep 2014; 4:5319. [PMID: 24936723 PMCID: PMC4060504 DOI: 10.1038/srep05319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/27/2014] [Indexed: 11/08/2022] Open
Abstract
High-temperature superconductors exhibit a characteristic hourglass-shaped spectrum of magnetic fluctuations which most likely contribute to the pairing glue in the cuprates. Recent neutron scattering experiments in strongly underdoped compounds have revealed a significant low energy anisotropy of these fluctuations which we explain by a model in which topological defects of the antiferromagnet clump to producing domain wall segments with ferronematic order. This state does not invoke global charge order but breaks C4 rotational and inversion symmetry. The incommensurability of the low doping charge-disordered state is in good agreement with experiment and interpolates smoothly with the incommensurability of the stripe phase at higher doping. Within linear spin-wave theory the dynamic structure factor is in very good agreement with inelastic neutron scattering data and can account for the observed energy dependent anisotropy.
Collapse
|
9
|
Sugai S, Takayanagi Y, Hayamizu N, Muroi T, Shiozaki R, Nohara J, Takenaka K, Okazaki K. Superconducting pairing and the pseudogap in the nematic dynamical stripe phase of La2-xSrxCuO4. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:475701. [PMID: 24166932 DOI: 10.1088/0953-8984/25/47/475701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Fully absorption coefficient corrected Raman spectra were obtained in La2-xSrxCuO4. The B1g spectra have a Fleury-Loudon type two-magnon peak (resonant term) whose energy decreases from 3180 cm(-1) (394 meV) to 440 cm(-1) (55 meV) on increasing the carrier density from x = 0 to 0.25, while the B2g spectra have a 1000-3500 cm(-1) (124-434 meV) hump (hill) whose lower-edge energy increases from x = 0 to 0.115 and then stays constant to x = 0.25. The B2g hump is assigned to the electronic scattering (non-resonant term) of the spectral function with magnetic self-energy. The completely different carrier density dependence arises from anisotropic magnetic excitations of spin-charge stripes. The B1g spectra were assigned to the sum of k ∥ and k⊥ stripe excitations and the B2g spectra to k⊥ stripe excitations according to the calculation by Seibold and Lorenzana (2006 Phys. Rev. B 73 144515). The k ∥ and k⊥ stripe excitations in fluctuating spin-charge stripes were separately detected for the first time. The appearance of only k⊥ stripe excitations in the electronic scattering arises from the charge hopping perpendicular to the stripe. This is the same direction as the Burgers vector of the edge dislocation in metal. The successive charge hopping in the Burgers vector direction across the charge stripes may cause Cooper pairs as predicted by Zaanen et al (2004 Ann. Phys. 310 181). Indeed, this is supported by the experimental fact that the superconducting coherent length coincides with the inter-charge stripe distance in the wide carrier density range. The one-directional charge hopping perpendicular to the stripe causes the flat Fermi surface and the pseudogap near (π,0) and (0,π), but the states around (π/2,π/2) cannot be produced. The low-energy Raman scattering disclosed that the electronic states at the Fermi arc around (π/2,π/2) are coupled to the A1g soft phonon of the tetragonal-orthorhombic phase transition. This suggests that the Fermi arc is produced by the electron-phonon interaction. All the present Raman data suggest that Cooper pairs are formed at moving edge dislocations of dynamical charge stripes.
Collapse
Affiliation(s)
- S Sugai
- Department of Physics, Arts and Science, Petroleum Institute, PO Box 2533, Abu Dhabi, UAE. Department of Physics, Faculty of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Ghiringhelli G, Le Tacon M, Minola M, Blanco-Canosa S, Mazzoli C, Brookes NB, De Luca GM, Frano A, Hawthorn DG, He F, Loew T, Moretti Sala M, Peets DC, Salluzzo M, Schierle E, Sutarto R, Sawatzky GA, Weschke E, Keimer B, Braicovich L. Long-Range Incommensurate Charge Fluctuations in (Y,Nd)Ba2Cu3O6+x. Science 2012; 337:821-5. [PMID: 22798406 DOI: 10.1126/science.1223532] [Citation(s) in RCA: 262] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- G Ghiringhelli
- CNR-SPIN, Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Yamase H, Metzner W. Fermi-surface truncation from thermal nematic fluctuations. PHYSICAL REVIEW LETTERS 2012; 108:186405. [PMID: 22681096 DOI: 10.1103/physrevlett.108.186405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Indexed: 06/01/2023]
Abstract
We analyze how thermal fluctuations near a finite temperature nematic phase transition affect the spectral function A(k,ω) for single-electron excitations in a two-dimensional metal. Perturbation theory yields a splitting of the quasiparticle peak with a d-wave form factor, reminiscent of a pseudogap. We present a resummation of contributions to all orders in the Gaussian fluctuation regime. Instead of a splitting, the resulting spectral function exhibits a pronounced broadening of the quasiparticle peak, which varies strongly around the Fermi surface and vanishes upon approaching the Brillouin-zone diagonal. The Fermi surface obtained from a Brillouin-zone plot of A(k,0) seems truncated to Fermi arcs.
Collapse
Affiliation(s)
- Hiroyuki Yamase
- National Institute for Materials Science, Tsukuba 305-0047, Japan
| | | |
Collapse
|
12
|
Raichle M, Reznik D, Lamago D, Heid R, Li Y, Bakr M, Ulrich C, Hinkov V, Hradil K, Lin CT, Keimer B. Highly anisotropic anomaly in the dispersion of the copper-oxygen bond-bending phonon in superconducting YBa2Cu3O7 from inelastic neutron scattering. PHYSICAL REVIEW LETTERS 2011; 107:177004. [PMID: 22107567 DOI: 10.1103/physrevlett.107.177004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Indexed: 05/31/2023]
Abstract
Motivated by predictions of a substantial contribution of the "buckling" vibration of the CuO(2) layers to d-wave superconductivity in the cuprates, we have performed an inelastic neutron scattering study of this phonon in an array of untwinned crystals of YBa(2)Cu(3)O(7). The data reveal a pronounced softening of the phonon at the in-plane wave vector q=(0,0.3) upon cooling below ~105 K, but no corresponding anomaly at q=(0.3,0). Based on the observed in-plane anisotropy, we argue that the electron-phonon interaction responsible for this anomaly supports an electronic instability associated with a uniaxial charge-density modulation and does not mediate d-wave superconductivity.
Collapse
Affiliation(s)
- M Raichle
- Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Nematy M, Mohajeri SAR, Moghadam SA, Safarian M, Norouzy A, Parizadeh SMR, Azarpazhooh MR, Siadat Z, Gharbi NS, Mobarhan MG. Nutritional status in intensive care unit patients: a prospective clinical cohort pilot study. MEDITERRANEAN JOURNAL OF NUTRITION AND METABOLISM 2011. [DOI: 10.1007/s12349-011-0071-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
14
|
Carlson E, Dahmen K. Using disorder to detect locally ordered electron nematics via hysteresis. Nat Commun 2011; 2:379. [DOI: 10.1038/ncomms1375] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 06/03/2011] [Indexed: 11/09/2022] Open
|
15
|
Galanakis D, Khatami E, Mikelsons K, Macridin A, Moreno J, Browne DA, Jarrell M. Quantum criticality and incipient phase separation in the thermodynamic properties of the Hubbard model. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2011; 369:1670-1686. [PMID: 21422020 DOI: 10.1098/rsta.2010.0228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Transport measurements on the cuprates suggest the presence of a quantum critical point (QCP) hiding underneath the superconducting dome near optimal hole doping. We provide numerical evidence in support of this scenario via a dynamical cluster quantum Monte Carlo study of the extended two-dimensional Hubbard model. Single-particle quantities, such as the spectral function, the quasi-particle weight and the entropy, display a crossover between two distinct ground states: a Fermi liquid at low filling and a non-Fermi liquid with a pseudo-gap at high filling. Both states are found to cross over to a marginal Fermi-liquid state at higher temperatures. For finite next-nearest-neighbour hopping t', we find a classical critical point at temperature T(c). This classical critical point is found to be associated with a phase-separation transition between a compressible Mott gas and an incompressible Mott liquid corresponding to the Fermi liquid and the pseudo-gap state, respectively. Since the critical temperature T(c) extrapolates to zero as t' vanishes, we conclude that a QCP connects the Fermi liquid to the pseudo-gap region, and that the marginal Fermi-liquid behaviour in its vicinity is the analogue of the supercritical region in the liquid-gas transition.
Collapse
Affiliation(s)
- D Galanakis
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LO 70803, USA.
| | | | | | | | | | | | | |
Collapse
|
16
|
Sun K, Lawler MJ, Kim EA. Spin-charge interplay in electronic liquid crystals: fluctuating spin stripe driven by charge nematic ordering. PHYSICAL REVIEW LETTERS 2010; 104:106405. [PMID: 20366443 DOI: 10.1103/physrevlett.104.106405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 01/06/2010] [Indexed: 05/29/2023]
Abstract
We study the interplay between charge and spin ordering in electronic liquid crystalline states with a particular emphasis on fluctuating spin stripe phenomena observed in recent neutron scattering experiments. Based on a phenomenological model, we propose that charge nematic ordering is indeed behind the formation of temperature dependent incommensurate inelastic peaks near wave vector (pi, pi) in the dynamic structure factor of YBa(2)Cu(3)O(6+y). We strengthen this claim by providing a compelling fit to the experimental data.
Collapse
Affiliation(s)
- Kai Sun
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, USA
| | | | | |
Collapse
|
17
|
Jakubczyk P, Metzner W, Yamase H. Turning a first order quantum phase transition continuous by fluctuations: general flow equations and application to d-wave Pomeranchuk instability. PHYSICAL REVIEW LETTERS 2009; 103:220602. [PMID: 20366082 DOI: 10.1103/physrevlett.103.220602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Indexed: 05/29/2023]
Abstract
We derive renormalization group equations which allow us to treat order parameter fluctuations near quantum phase transitions in cases where an expansion in powers of the order parameter is not possible. As a prototypical application, we analyze the nematic transition driven by a d-wave Pomeranchuk instability in a two-dimensional electron system. We find that order parameter fluctuations suppress the first order character of the nematic transition obtained at low temperatures in mean-field theory, so that a continuous transition leading to quantum criticality can emerge.
Collapse
Affiliation(s)
- P Jakubczyk
- Max-Planck-Institute for Solid State Research, D-70569 Stuttgart, Germany.
| | | | | |
Collapse
|
18
|
Yamase H. Self-masking of spontaneous symmetry breaking in layer materials. PHYSICAL REVIEW LETTERS 2009; 102:116404. [PMID: 19392222 DOI: 10.1103/physrevlett.102.116404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Indexed: 05/27/2023]
Abstract
We study d-wave Fermi-surface deformations (dFSD), the so-called Pomeranchuk instability, on bilayer and infinite-layer square lattices. Since the order parameter of the dFSD has Ising symmetry, there are two stacking patterns along the c axis: (+, +) and (+, -). We find that, as long as the c axis dispersion is finite at the saddle points of the in-plane band dispersion, the (+, -) stacking is usually favored independently on the details of interlayer coupling, yielding no macroscopic anisotropy. The dFSD provides unique spontaneous symmetry breaking that is self-masked in layer materials.
Collapse
Affiliation(s)
- Hiroyuki Yamase
- Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| |
Collapse
|
19
|
Hinkov V, Haug D, Fauqué B, Bourges P, Sidis Y, Ivanov A, Bernhard C, Lin CT, Keimer B. Electronic liquid crystal state in the high-temperature superconductor YBa2Cu3O6.45. Science 2008; 319:597-600. [PMID: 18187621 DOI: 10.1126/science.1152309] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Electronic phases with symmetry properties matching those of conventional liquid crystals have recently been discovered in transport experiments on semiconductor heterostructures and metal oxides at millikelvin temperatures. We report the spontaneous onset of a one-dimensional, incommensurate modulation of the spin system in the high-transition-temperature superconductor YBa2Cu3O6.45 upon cooling below approximately 150 kelvin, whereas static magnetic order is absent above 2 kelvin. The evolution of this modulation with temperature and doping parallels that of the in-plane anisotropy of the resistivity, indicating an electronic nematic phase that is stable over a wide temperature range. The results suggest that soft spin fluctuations are a microscopic route toward electronic liquid crystals and that nematic order can coexist with high-temperature superconductivity in underdoped cuprates.
Collapse
Affiliation(s)
- V Hinkov
- Max-Planck-Institut für Festkörperforschung, Heisenberg-strasse 1, D-70569 Stuttgart, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Christensen NB, Rønnow HM, Mesot J, Ewings RA, Momono N, Oda M, Ido M, Enderle M, McMorrow DF, Boothroyd AT. Nature of the magnetic order in the charge-ordered cuprate La1.48Nd0.4Sr0.12CuO4. PHYSICAL REVIEW LETTERS 2007; 98:197003. [PMID: 17677652 DOI: 10.1103/physrevlett.98.197003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Indexed: 05/16/2023]
Abstract
Using polarized neutron scattering we establish that the magnetic order in La(1.48)Nd(0.4)Sr(0.12)CuO(4) is either (i) one dimensionally modulated and collinear, consistent with the stripe model or (ii) two dimensionally modulated with a novel noncollinear structure. The measurements rule out a number of alternative models characterized by 2D electronic order or 1D helical spin order. The low-energy spin excitations are found to be primarily transversely polarized relative to the stripe ordered state, consistent with conventional spin waves.
Collapse
Affiliation(s)
- N B Christensen
- Laboratory for Neutron Scattering, ETH Zurich & Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Zhao HJ, Li J. Difficulty in the Fermi-liquid-type theory for the in-plane magnetic anisotropy of untwinned YBa2Cu3O6.85 superconductors. PHYSICAL REVIEW LETTERS 2007; 98:139701; discussion 139702. [PMID: 17501247 DOI: 10.1103/physrevlett.98.139701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Indexed: 05/15/2023]
Affiliation(s)
- Hou-Jun Zhao
- National Key Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | | |
Collapse
|
22
|
Dell'Anna L, Metzner W. Electrical resistivity near Pomeranchuk instability in two dimensions. PHYSICAL REVIEW LETTERS 2007; 98:136402. [PMID: 17501223 DOI: 10.1103/physrevlett.98.136402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Indexed: 05/15/2023]
Abstract
We analyze the dc charge transport in the quantum critical regime near a d-wave Pomeranchuk instability in two dimensions. The transport decay rate is linear in temperature everywhere on the Fermi surface except at cold spots on the Brillouin zone diagonal. For pure systems, this leads to a dc resistivity proportional to T(3/2) in the low-temperature limit. In the presence of impurities the residual impurity resistance at T=0 is approached linearly at low temperatures.
Collapse
Affiliation(s)
- Luca Dell'Anna
- Max-Planck-Institute for Solid State Research, D-70569 Stuttgart, Germany
| | | |
Collapse
|
23
|
Vojta M, Vojta T, Kaul RK. Spin excitations in fluctuating stripe phases of doped cuprate superconductors. PHYSICAL REVIEW LETTERS 2006; 97:097001. [PMID: 17026392 DOI: 10.1103/physrevlett.97.097001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Indexed: 05/12/2023]
Abstract
Using a phenomenological lattice model of coupled spin and charge modes, we determine the spin susceptibility in the presence of fluctuating stripe charge order. We assume the charge fluctuations to be slow compared to those of the spins, and combine Monte Carlo simulations for the charge order parameter with exact diagonalization of the spin sector. Our calculations unify the spin dynamics of both static and fluctuating stripe phases and support the notion of a universal spin excitation spectrum in doped cuprate superconductors.
Collapse
Affiliation(s)
- Matthias Vojta
- Institut für Theorie der Kondensierten Materie, Universität Karlsruhe, 76128 Karlsruhe, Germany
| | | | | |
Collapse
|
24
|
Pailhès S, Ulrich C, Fauqué B, Hinkov V, Sidis Y, Ivanov A, Lin CT, Keimer B, Bourges P. Doping dependence of bilayer resonant spin excitations in (Y, Ca)Ba2Cu3O6+x. PHYSICAL REVIEW LETTERS 2006; 96:257001. [PMID: 16907334 DOI: 10.1103/physrevlett.96.257001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Indexed: 05/11/2023]
Abstract
Resonant magnetic modes with odd and even symmetries were studied by inelastic neutron scattering experiments in the bilayer high-Tc superconductor Y1-xCa+Ba2Cu3O6+y over a wide doping range. The threshold of the spin excitation continuum in the superconducting state, deduced from the energies and spectral weights of both modes, is compared with the superconducting d-wave gap, deduced from electronic Raman scattering in the B1g symmetry on the same samples. Above a critical doping level of delta approximately =0.19, both mode energies and the continuum threshold coincide. We find a simple scaling relationship between the characteristic energies and spectral weights of both modes, which indicates that the resonant modes are bound states in the superconducting energy gap, as predicted by the spin-exciton model of the resonant mode.
Collapse
Affiliation(s)
- S Pailhès
- Laboratoire Léon Brillouin, CEA-CNRS, CE-Saclay, 91191 Gif sur Yvette, France
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Fauqué B, Sidis Y, Hinkov V, Pailhès S, Lin CT, Chaud X, Bourges P. Magnetic order in the pseudogap phase of high-Tc superconductors. PHYSICAL REVIEW LETTERS 2006; 96:197001. [PMID: 16803131 DOI: 10.1103/physrevlett.96.197001] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Indexed: 05/10/2023]
Abstract
One of the leading issues in high-T(c) superconductors is the origin of the pseudogap phase in underdoped cuprates. Using polarized elastic neutron diffraction, we identify a novel magnetic order in the YB(2)Cu(3)O(6+) system. The observed magnetic order preserves translational symmetry of the lattice as proposed for orbital moments in the circulating current theory of the pseudogap state. To date, it is the first direct evidence of a hidden order parameter characterizing the pseudogap phase in high-T(c) cuprates.
Collapse
Affiliation(s)
- B Fauqué
- Laboratoire Léon Brillouin, CEA-CNRS, CEA-Saclay, Gif sur Yvette, France
| | | | | | | | | | | | | |
Collapse
|
26
|
Reznik D, Pintschovius L, Ito M, Iikubo S, Sato M, Goka H, Fujita M, Yamada K, Gu GD, Tranquada JM. Electron-phonon coupling reflecting dynamic charge inhomogeneity in copper oxide superconductors. Nature 2006; 440:1170-3. [PMID: 16641991 DOI: 10.1038/nature04704] [Citation(s) in RCA: 269] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Accepted: 03/02/2006] [Indexed: 11/09/2022]
Abstract
The attempt to understand copper oxide superconductors is complicated by the presence of multiple strong interactions in these systems. Many believe that antiferromagnetism is important for superconductivity, but there has been renewed interest in the possible role of electron-lattice coupling. The conventional superconductor MgB2 has a very strong electron-lattice coupling, involving a particular vibrational mode (phonon) that was predicted by standard theory and confirmed quantitatively by experiment. Here we present inelastic scattering measurements that show a similarly strong anomaly in the Cu-O bond-stretching phonon in the copper oxide superconductors La(2-x)Sr(x)CuO4 (with x = 0.07, 0.15). Conventional theory does not predict such behaviour. The anomaly is strongest in La(1.875)Ba(0.125)CuO4 and La(1.48)Nd(0.4)Sr(0.12)CuO4, compounds that exhibit spatially modulated charge and magnetic order, often called stripe order; it occurs at a wave vector corresponding to the charge order. These results suggest that this giant electron-phonon anomaly, which is absent in undoped and over-doped non-superconductors, is associated with charge inhomogeneity. It follows that electron-phonon coupling may be important to our understanding of superconductivity, although its contribution is likely to be indirect.
Collapse
Affiliation(s)
- D Reznik
- Forschungszentrum Karlsruhe, Institut für Festkörperphysik, POB 3640, D-76021 Karlsruhe, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Vrang N, Madsen AN, Tang-Christensen M, Hansen G, Larsen PJ. PYY(3-36) reduces food intake and body weight and improves insulin sensitivity in rodent models of diet-induced obesity. Am J Physiol Regul Integr Comp Physiol 2006; 291:R367-75. [PMID: 16914421 DOI: 10.1152/ajpregu.00726.2005] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The gut hormone peptide YY (PYY) was recently proposed to comprise an endogenous satiety factor. We have studied acute anorectic functions of PYY(3-36) in mice and rats, as well as metabolic effects of chronic PYY(3-36) administration to diet-induced obese (DIO) mice and rats. A single intraperitoneal injection of PYY(3-36) inhibited food intake in mice, but not in rats. We next investigated the effects of increasing doses (100, 300, and 1,000 microg.kg-1.day-1) of PYY(3-36) administered subcutaneously via osmotic minipumps on food intake and body weight in DIO C57BL/6J mice. Whereas only the highest dose (1,000 microg.kg-1.day-1) of PYY(3-36) significantly reduced food intake over the first 3 days, body weight gain was dose dependently reduced, and on day 28 the group treated with 1,000 microg.kg-1.day-1 PYY(3-36) weighed approximately 10% less than the vehicle-treated group. Mesenteric, epididymal, retroperitoneal, and inguinal fat pad weight was dose dependently reduced. Subcutaneous administration of PYY(3-36) (250 and 1,000 microg.kg-1.day-1) for 28 days reduced body weight and improved glycemic control in glucose-intolerant DIO rats. Neither 250 nor 1,000 microg/kg PYY(3-36) elicited a conditioned taste aversion in male rats.
Collapse
Affiliation(s)
- Niels Vrang
- Rheoscience, Glerupvej 2, 2610 Rødovre, Denmark.
| | | | | | | | | |
Collapse
|
28
|
Borisenko SV, Kordyuk AA, Zabolotnyy V, Geck J, Inosov D, Koitzsch A, Fink J, Knupfer M, Büchner B, Hinkov V, Lin CT, Keimer B, Wolf T, Chiuzbăian SG, Patthey L, Follath R. Kinks, nodal bilayer splitting, and interband scattering in YBa2Cu3O(6+x). PHYSICAL REVIEW LETTERS 2006; 96:117004. [PMID: 16605854 DOI: 10.1103/physrevlett.96.117004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Indexed: 05/08/2023]
Abstract
We apply the new-generation angle-resolved photoemission spectroscopy methodology to the most widely studied cuprate superconductor YBa2Cu3O(6+x). Considering the nodal direction, we found noticeable renormalization effects known as kinks both in the quasiparticle dispersion and scattering rate, the bilayer splitting, and evidence for strong interband scattering--all the characteristic features of the nodal quasiparticles detected earlier in Bi2Sr2CaCu2O(8+delta). The typical energy scale and the doping dependence of the kinks clearly point to their intimate relation with the spin-1 resonance seen in the neutron scattering experiments. Our findings strongly suggest a universality of the electron dynamics in the bilayer superconducting cuprates and a dominating role of the spin fluctuations in the formation of the quasiparticles along the nodal direction.
Collapse
Affiliation(s)
- S V Borisenko
- IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Wilson JA. Structural matters in HTSC: the origin and form of stripe organization and checkerboarding. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:R69-R99. [PMID: 21697557 DOI: 10.1088/0953-8984/18/6/r02] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The paper deals with the controversial charge and spin self-organization phenomena in the HTSC cuprates, of which neutron, x-ray, STM and ARPES experiments give complementary, sometimes apparently contradictory glimpses. The examination has been set in the context of the boson-fermion, negative-U understanding of HTSC advocated over many years by the author. Stripe models are developed which are 2-q in nature and diagonal in form. For such a geometry to be compatible with the data rests upon both the spin and charge arrays being face-centred. Various special doping concentrations are closely looked at, in particular p = 0.1836 or 9/49, which is associated with the maximization of the superconducting condensation energy and the termination of the pseudogap regime. The stripe models are dictated by real space organization of the holes, whereas the dispersionless checkerboarding is interpreted in terms of correlation driven collapse of normal Fermi surface behaviour and response functions. The incommensurate spin diffraction below the 'resonance energy' is seen as in no way expressing spin-wave physics or Fermi surface nesting, but is driven by charge and strain (Jahn-Teller) considerations, and it stands virtually without dispersion. The apparent dispersion comes from the downward dispersion of the resonance peak, and the growth of a further incoherent commensurate peak pursuant upon the falling level of charge stripe organization under excitation.
Collapse
Affiliation(s)
- John A Wilson
- H H Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK
| |
Collapse
|
30
|
Lindgård PA. Spiral spin state in high-temperature copper-oxide superconductors: evidence from neutron scattering measurements. PHYSICAL REVIEW LETTERS 2005; 95:217001. [PMID: 16384170 DOI: 10.1103/physrevlett.95.217001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Indexed: 05/05/2023]
Abstract
An effective spiral spin phase ground state provides a new paradigm for the high-temperature superconducting cuprates. It accounts for the recent neutron scattering observations of spin excitations regarding both the energy dispersion and the intensities, including the "universal" rotation by 45 degrees around the resonance energy . The intensity has a 2D character even in a single twin crystal. The value of is related to the nesting properties of the Fermi surface. The excitations above are shown to be due to in-plane spin fluctuations, a testable difference from the stripe model. The form of the exchange interaction function reveals the effects of the Fermi surface, and the unique shape predicts large quantum spin fluctuations in the ground state.
Collapse
Affiliation(s)
- Per-Anker Lindgård
- Materials Research Department, Risø National Laboratory, 4000 Roskilde, Denmark.
| |
Collapse
|
31
|
Schüssler-Langeheine C, Schlappa J, Tanaka A, Hu Z, Chang CF, Schierle E, Benomar M, Ott H, Weschke E, Kaindl G, Friedt O, Sawatzky GA, Lin HJ, Chen CT, Braden M, Tjeng LH. Spectroscopy of stripe order in La1.8Sr0.2NiO4 using resonant soft x-ray diffraction. PHYSICAL REVIEW LETTERS 2005; 95:156402. [PMID: 16241744 DOI: 10.1103/physrevlett.95.156402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Indexed: 05/05/2023]
Abstract
Strong resonant enhancements of the charge-order and spin-order superstructure-diffraction intensities in La1.8Sr0.2NiO4 are observed when x-ray energies in the vicinity of the Ni L2,3 absorption edges are used. The pronounced photon-energy and polarization dependences of these diffraction intensities allow for a critical determination of the local symmetry of the ordered spin and charge carriers. We found that not only the antiferromagnetic order but also the charge-order superstructure resides within the NiO2 layers; the holes are mainly located on in-plane oxygens surrounding a Ni2+ site with the spins coupled antiparallel in close analogy to Zhang-Rice singlets in the cuprates.
Collapse
Affiliation(s)
- C Schüssler-Langeheine
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
McLaughlin AC, Sher F, Attfield JP. Negative lattice expansion from the superconductivity–antiferromagnetism crossover in ruthenium copper oxides. Nature 2005; 436:829-32. [PMID: 16094364 DOI: 10.1038/nature03828] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Accepted: 05/17/2005] [Indexed: 11/09/2022]
Abstract
The mechanism of high-transition-temperature (high-T(c)) superconductivity in doped copper oxides is an enduring problem. Antiferromagnetism is established as the competing order, but the relationship between the two states in the intervening 'pseudogap' regime has become a central puzzle. The role of the crystal lattice, which is important in conventional superconductors, also remains unclear. Here we report an anomalous increase of the distance between copper oxide planes on cooling, which results in negative thermal volume expansion, for layered ruthenium copper oxides that have been doped to the boundary of antiferromagnetism and superconductivity. We propose that a crossover between these states is driven by spin ordering in the ruthenium oxide layers, revealing a novel mechanism for negative lattice expansion in solids. The differences in volume and lattice strain between the distinct superconducting and antiferromagnetic states can account for the phase segregation phenomena found extensively in low-doped copper oxides, and show that Cooper pair formation is coupled to the lattice. Unusually large variations of resistivity with magnetic field are found in these ruthenium copper oxides at low temperatures through coupling between the ordered Ru and Cu spins.
Collapse
Affiliation(s)
- A C McLaughlin
- Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, UK
| | | | | |
Collapse
|
33
|
Ishii K, Tsutsui K, Endoh Y, Tohyama T, Kuzushita K, Inami T, Ohwada K, Maekawa S, Masui T, Tajima S, Murakami Y, Mizuki J. Mott gap excitations in twin-free YBa2Cu3O7-delta (Tc=93 K) studied by resonant inelastic x-ray scattering. PHYSICAL REVIEW LETTERS 2005; 94:187002. [PMID: 15904402 DOI: 10.1103/physrevlett.94.187002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Indexed: 05/02/2023]
Abstract
Mott gap excitations in the optimally doped high-T(c) superconductor YBa(2)Cu(3)O(7-delta) (T(c)=93 K) have been studied by the resonant inelastic x-ray scattering method. Anisotropic spectra in the ab plane are observed in a twin-free crystal. The excitation from the one-dimensional CuO chain is enhanced at 2 eV near the zone boundary of the b* direction, while the excitation from the CuO2 plane is broad at 1.5-4 eV and almost independent of the momentum transfer. Theoretical calculations based on the one-dimensional and two-dimensional Hubbard model reproduces the observed spectra when different values of the on-site Coulomb energy are assumed. The Mott gap of the CuO chain site is found to be much smaller than that of the CuO2 plane site.
Collapse
Affiliation(s)
- K Ishii
- Synchrotron Radiation Research Center, Japan Atomic Energy Research Institute, Hyogo 679-5148, Japan.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Eremin I, Manske D. Fermi-liquid-based theory for the in-plane magnetic anisotropy in untwinned high-Tc superconductors. PHYSICAL REVIEW LETTERS 2005; 94:067006. [PMID: 15783771 DOI: 10.1103/physrevlett.94.067006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Indexed: 05/24/2023]
Abstract
Using a generalized RPA-type theory we calculate the in-plane anisotropy of the magnetic excitations in hole-doped high-Tc superconductors. Extending our earlier Fermi-liquid-based studies on the resonance peak by inclusion of orthorhombicity we still find two-dimensional spin excitations, however, being strongly anisotropic. This reflects the underlying anisotropy of the hopping matrix elements and of the resultant superconducting gap function. We compare our calculations with new experimental data on fully untwinned YBa2Cu3O6.85 and find good agreement. Our results are in contrast to earlier interpretations on the in-plane anisotropy in terms of stripes [H. Mook, Nature (London) 404, 729 (2000)], but reveal a conventional solution to this important problem.
Collapse
Affiliation(s)
- I Eremin
- Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | | |
Collapse
|
35
|
Yamase H. Excitation spectrum of d-wave Fermi surface deformation. PHYSICAL REVIEW LETTERS 2004; 93:266404. [PMID: 15697999 DOI: 10.1103/physrevlett.93.266404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Indexed: 05/24/2023]
Abstract
Several instabilities competing with the d-wave singlet pairing were proposed for high-Tc cuprates. One of them is the d-wave Fermi surface deformation (dFSD), which is generated by forward scattering. In this Letter, correlation functions of the dFSD are calculated within the random phase approximation. In the normal state, the excitation spectrum shows a low energy peak, which smoothly connects to critical fluctuations of the dFSD at lower temperature. The competition with the d-wave pairing, however, blocks the critical fluctuations. The whole spectral weight is transferred to high energy and a pronounced peak appears there in the d-wave pairing state. This peak is an overdamped collective mode of the dFSD and can grow to become a resonance mode at moderate finite wave vectors.
Collapse
Affiliation(s)
- Hiroyuki Yamase
- RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama 351-0198, Japan
| |
Collapse
|
36
|
Uhrig GS, Schmidt KP, Grüninger M. Unifying magnons and triplons in stripe-ordered cuprate superconductors. PHYSICAL REVIEW LETTERS 2004; 93:267003. [PMID: 15698009 DOI: 10.1103/physrevlett.93.267003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2004] [Indexed: 05/24/2023]
Abstract
Based on a two-dimensional model of coupled two-leg spin ladders, we derive a unified picture of recent neutron scattering data of stripe-ordered La15/8Ba1/8CuO4, namely, of the low-energy magnons around the superstructure satellites and of the triplon excitations at higher energies. The resonance peak at the antiferromagnetic wave vector Q(AF) in the stripe-ordered phase corresponds to a saddle point in the dispersion of the magnetic excitations. Quantitative agreement with the neutron data is obtained for J=130-160 meV and Jcyc/J=0.2-0.25.
Collapse
Affiliation(s)
- G S Uhrig
- Institut für Theoretische Physik, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln, Germany
| | | | | |
Collapse
|