1
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Scheie A, Benton O, Taillefumier M, Jaubert LDC, Sala G, Jalarvo N, Koohpayeh SM, Shannon N. Dynamical Scaling as a Signature of Multiple Phase Competition in Yb_{2}Ti_{2}O_{7}. PHYSICAL REVIEW LETTERS 2022; 129:217202. [PMID: 36461963 DOI: 10.1103/physrevlett.129.217202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 07/25/2022] [Accepted: 10/28/2022] [Indexed: 06/17/2023]
Abstract
Yb_{2}Ti_{2}O_{7} is a celebrated example of a pyrochlore magnet with highly frustrated, anisotropic exchange interactions. To date, attention has largely focused on its unusual, static properties, many of which can be understood as coming from the competition between different types of magnetic order. Here we use inelastic neutron scattering with exceptionally high energy resolution to explore the dynamical properties of Yb_{2}Ti_{2}O_{7}. We find that spin correlations exhibit dynamical scaling, analogous to behavior found near to a quantum critical point. We show that the observed scaling collapse can be explained within a phenomenological theory of multiple-phase competition, and confirm that a scaling collapse is also seen in semiclassical simulations of a microscopic model of Yb_{2}Ti_{2}O_{7}. These results suggest that dynamical scaling may be general to systems with competing ground states.
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Affiliation(s)
- A Scheie
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - O Benton
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, Dresden 01187, Germany
| | - M Taillefumier
- ETH Zurich, Swiss National Supercomputing Centre (CSCS), HIT G-floor Wolfgang-Pauli-Str. 27, 8093 Zurich, Switzerland
| | - L D C Jaubert
- CNRS, Université de Bordeaux, LOMA, UMR 5798, 33400 Talence, France
| | - G Sala
- Spallation Neutron Source, Second Target Station, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N Jalarvo
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S M Koohpayeh
- Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - N Shannon
- Theory of Quantum Matter Unit, Okinawa Institute of Science and Technology Graduate University, Onna son, Okinawa 904-0495, Japan
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2
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Yahne DR, Pereira D, Jaubert LDC, Sanjeewa LD, Powell M, Kolis JW, Xu G, Enjalran M, Gingras MJP, Ross KA. Understanding Reentrance in Frustrated Magnets: The Case of the Er_{2}Sn_{2}O_{7} Pyrochlore. PHYSICAL REVIEW LETTERS 2021; 127:277206. [PMID: 35061439 DOI: 10.1103/physrevlett.127.277206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 11/11/2021] [Indexed: 06/14/2023]
Abstract
Reentrance, the return of a system from an ordered phase to a previously encountered less-ordered one as a controlled parameter is continuously varied, is a recurring theme found in disparate physical systems, yet its microscopic cause is often not investigated thoroughly. Here, through detailed characterization and theoretical modeling, we uncover the microscopic mechanism behind reentrance in the strongly frustrated pyrochlore antiferromagnet Er_{2}Sn_{2}O_{7}. We use single crystal heat capacity measurements to expose that Er_{2}Sn_{2}O_{7} exhibits multiple instances of reentrance in its magnetic field B vs temperature T phase diagram for magnetic fields along three cubic high symmetry directions. Through classical Monte Carlo simulations, mean field theory, and classical linear spin-wave expansions, we argue that the origins of the multiple occurrences of reentrance observed in Er_{2}Sn_{2}O_{7} are linked to soft modes. These soft modes arise from phase competition and enhance thermal fluctuations that entropically stabilize a specific ordered phase, resulting in an increased transition temperature for certain field values and thus the reentrant behavior. Our work represents a detailed examination into the mechanisms responsible for reentrance in a frustrated magnet and may serve as a template for the interpretation of reentrant phenomena in other physical systems.
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Affiliation(s)
- D R Yahne
- Department of Physics, Colorado State University, 200 W. Lake Street, Fort Collins, Colorado 80523-1875, USA
| | - D Pereira
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - L D C Jaubert
- CNRS, Université de Bordeaux, LOMA, UMR 5798, 33400 Talence, France
| | - L D Sanjeewa
- Missouri Research Reactor, University of Missouri, Columbia, Missouri 65211, USA
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
| | - M Powell
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634-0973, USA
| | - J W Kolis
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634-0973, USA
| | - Guangyong Xu
- NIST Center for Neutron Research, National Institutue of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - M Enjalran
- Department of Physics, Southern Connecticut State University, 501 Crescent Street, New Haven, Connecticut 06515-1355, USA
| | - M J P Gingras
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- CIFAR, MaRS Centre, West Tower 661 University Avenue, Suite 505, Toronto, Ontario M5G 1M1, Canada
| | - K A Ross
- Department of Physics, Colorado State University, 200 W. Lake Street, Fort Collins, Colorado 80523-1875, USA
- CIFAR, MaRS Centre, West Tower 661 University Avenue, Suite 505, Toronto, Ontario M5G 1M1, Canada
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3
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Abstract
We use neutron scattering to show that ferromagnetism and antiferromagnetism coexist in the low T state of the pyrochlore quantum magnet [Formula: see text] While magnetic Bragg peaks evidence long-range static ferromagnetic order, inelastic scattering shows that short-range correlated antiferromagnetism is also present. Small-angle neutron scattering provides direct evidence for mesoscale magnetic structure that we associate with metastable antiferromagnetism. Classical Monte Carlo simulations based on exchange interactions inferred from [Formula: see text]-oriented high-field spin wave measurements confirm that antiferromagnetism is metastable within the otherwise ferromagnetic ground state. The apparent lack of coherent spin wave excitations and strong sensitivity to quenched disorder characterizing [Formula: see text] is a consequence of this multiphase magnetism.
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4
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Gaudet J, Smith EM, Dudemaine J, Beare J, Buhariwalla CRC, Butch NP, Stone MB, Kolesnikov AI, Xu G, Yahne DR, Ross KA, Marjerrison CA, Garrett JD, Luke GM, Bianchi AD, Gaulin BD. Quantum Spin Ice Dynamics in the Dipole-Octupole Pyrochlore Magnet Ce_{2}Zr_{2}O_{7}. PHYSICAL REVIEW LETTERS 2019; 122:187201. [PMID: 31144900 DOI: 10.1103/physrevlett.122.187201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/15/2019] [Indexed: 06/09/2023]
Abstract
Neutron scattering measurements on the pyrochlore magnet Ce_{2}Zr_{2}O_{7} reveal an unusual crystal field splitting of its lowest J=5/2 multiplet, such that its ground-state doublet is composed of m_{J}=±3/2, giving these doublets a dipole-octupole (DO) character with local Ising anisotropy. Its magnetic susceptibility shows weak antiferromagnetic correlations with θ_{CW}=-0.4(2) K, leading to a naive expectation of an all-in, all-out ordered state at low temperatures. Instead, our low-energy inelastic neutron scattering measurements show a dynamic quantum spin ice state, with suppressed scattering near |Q|=0, and no long-range order at low temperatures. This is consistent with recent theory predicting symmetry-enriched U(1) quantum spin liquids for such DO doublets decorating the pyrochlore lattice. Finally, we show that disorder, especially oxidation of powder samples, is important in Ce_{2}Zr_{2}O_{7} and could play an important role in the low-temperature behavior of this material.
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Affiliation(s)
- J Gaudet
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
- Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Center for Neutron Research, National Institute of Standards and Technology, MS 6100 Gaithersburg, Maryland 20899, USA
| | - E M Smith
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - J Dudemaine
- Département de Physique, Université de Montréal, 2900 Boulevard Édouard-Montpetit, Montréal, Quebec, H3T 1J4, Canada
| | - J Beare
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - C R C Buhariwalla
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - N P Butch
- Center for Neutron Research, National Institute of Standards and Technology, MS 6100 Gaithersburg, Maryland 20899, USA
| | - M B Stone
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A I Kolesnikov
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Guangyong Xu
- Center for Neutron Research, National Institute of Standards and Technology, MS 6100 Gaithersburg, Maryland 20899, USA
| | - D R Yahne
- Department of Physics, Colorado State University, 200 West Lake Street, Fort Collins, Colorado 80523-1875, USA
| | - K A Ross
- Department of Physics, Colorado State University, 200 West Lake Street, Fort Collins, Colorado 80523-1875, USA
- Canadian Institute for Advanced Research, 661 University Avenue, Toronto, Ontario, M5G 1M1, Canada
| | - C A Marjerrison
- Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - J D Garrett
- Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - G M Luke
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
- Canadian Institute for Advanced Research, 661 University Avenue, Toronto, Ontario, M5G 1M1, Canada
| | - A D Bianchi
- Département de Physique, Université de Montréal, 2900 Boulevard Édouard-Montpetit, Montréal, Quebec, H3T 1J4, Canada
- Regroupement Québécois sur les Matériaux de Pointe (RQMP), Quebec, H3T 3J7, Canada
| | - B D Gaulin
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
- Canadian Institute for Advanced Research, 661 University Avenue, Toronto, Ontario, M5G 1M1, Canada
- Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
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5
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Abstract
The pyrochlore structure (A2B2O7) has been an object of consistent study by materials scientists largely due to the stability of the cubic lattice with respect to a wide variety of chemical species on the A or B sites. The criterion for stability under ambient conditions is controlled by the ratio of these cations, which is empirically 1.36 < RA/RB < 1.71. However, under applied pressure synthesis conditions, the pyrochlore lattice is stable up to RA/RB ∼ 2.30, opening up possibilities for new compounds. In this review, we will highlight recent work in exploring new rare-earth pyrochlores such as the germanates RE2Ge2O7 and platinates RE2Pt2O7. We highlight recent discoveries made in these pyrochlores such as highly correlated spin ice behavior, spin liquid ground states, and exotic magnetic ordering.
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Wang Q, Ghasemi A, Scheie A, Koohpayeh SM. Synthesis, crystal growth and characterization of the pyrochlore Er 2Ti 2O 7. CrystEngComm 2019. [DOI: 10.1039/c8ce01885e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A stoichiometric and high crystalline quality Er2Ti2O7 single crystal was successfully grown using the traveling solvent floating zone technique for the first time.
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Affiliation(s)
- Q. Wang
- Institute for Quantum Matter
- Department of Physics and Astronomy
- Johns Hopkins University
- Baltimore
- USA
| | - A. Ghasemi
- Institute for Quantum Matter
- Department of Physics and Astronomy
- Johns Hopkins University
- Baltimore
- USA
| | - A. Scheie
- Institute for Quantum Matter
- Department of Physics and Astronomy
- Johns Hopkins University
- Baltimore
- USA
| | - S. M. Koohpayeh
- Institute for Quantum Matter
- Department of Physics and Astronomy
- Johns Hopkins University
- Baltimore
- USA
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7
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Hallas AM, Gaudet J, Butch NP, Xu G, Tachibana M, Wiebe CR, Luke GM, Gaulin BD. Phase Competition in the Palmer-Chalker XY Pyrochlore Er_{2}Pt_{2}O_{7}. PHYSICAL REVIEW LETTERS 2017; 119:187201. [PMID: 29219594 DOI: 10.1103/physrevlett.119.187201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Indexed: 06/07/2023]
Abstract
We report neutron scattering measurements on Er_{2}Pt_{2}O_{7}, a new addition to the XY family of frustrated pyrochlore magnets. Symmetry analysis of our elastic scattering data shows that Er_{2}Pt_{2}O_{7} orders into the k=0, Γ_{7} magnetic structure (the Palmer-Chalker state), at T_{N}=0.38 K. This contrasts with its sister XY pyrochlore antiferromagnets Er_{2}Ti_{2}O_{7} and Er_{2}Ge_{2}O_{7}, both of which order into Γ_{5} magnetic structures at much higher temperatures, T_{N}=1.2 and 1.4 K, respectively. In this temperature range, the magnetic heat capacity of Er_{2}Pt_{2}O_{7} contains a broad anomaly centered at T^{*}=1.5 K. Our inelastic neutron scattering measurements reveal that this broad heat capacity anomaly sets the temperature scale for strong short-range spin fluctuations. Below T_{N}=0.38 K, Er_{2}Pt_{2}O_{7} displays a gapped spin-wave spectrum with an intense, flat band of excitations at lower energy and a weak, diffusive band of excitations at higher energy. The flat band is well described by classical spin-wave calculations, but these calculations also predict sharp dispersive branches at higher energy, a striking discrepancy with the experimental data. This, in concert with the strong suppression of T_{N}, is attributable to enhanced quantum fluctuations due to phase competition between the Γ_{7} and Γ_{5} states that border each other within a classically predicted phase diagram.
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Affiliation(s)
- A M Hallas
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - J Gaudet
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - N P Butch
- Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, MS 6100, Gaithersburg, Maryland 20899, USA
| | - Guangyong Xu
- Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, MS 6100, Gaithersburg, Maryland 20899, USA
| | - M Tachibana
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Ibaraki, Japan
| | - C R Wiebe
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba R3B 2E9, Canada
- Canadian Institute for Advanced Research, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - G M Luke
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Canadian Institute for Advanced Research, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - B D Gaulin
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Canadian Institute for Advanced Research, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
- Brockhouse Institute for Materials Research, Hamilton, Ontario L8S 4M1, Canada
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