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Title: Magnetoelastically induced vibronic bound state in the spin-ice pyrochlore Ho 2 Ti 2 O 7

Abstract

The single-ion physics of Ho 2Ti 2O 7 is well understood to produce strong Ising anisotropy, which is an essential ingredient to its low-temperature spin-ice state. We present inelastic neutron scattering measurements on Ho 2Ti 2O 7 that reveal a clear inconsistency with its established single-ion Hamiltonian. Specifically, we show that a crystal-field doublet near 60 meV is split by approximately 3 meV. Furthermore, this crystal-field splitting is not isolated to Ho 2Ti 2O 7 but can also be found in its chemical pressure analogs Ho 2Ge 2O 7 and Ho 2Sn 2O 7. We demonstrate that the origin of this effect is a vibronic bound state, resulting from the entanglement of a phonon and crystal-field excitation. In conclusion, we derive the microscopic Hamiltonian that describes the magnetoelastic coupling and provides a quantitative description of the inelastic neutron spectra.

Authors:
 [1];  [1];  [1]; ORCiD logo [2]; ORCiD logo [3];  [4];  [5];  [6];  [7]
  1. McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy
  2. McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division
  4. National Inst. for Materials Science (NIMS), Tsukuba (Japan)
  5. Princeton Univ., NJ (United States). Dept. of Chemistry
  6. Princeton Univ., NJ (United States). Dept. of Chemistry; Princeton Univ., NJ (United States). Princeton Materials Inst.
  7. McMaster Univ., Hamilton, ON (Canada). Dept. of Physics and Astronomy; Canadian Inst. for Advanced Research, Toronto (Canada); Brockhouse Inst. for Materials Research, Hamilton, ON (Canada)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1470882
Alternate Identifier(s):
OSTI ID: 1460908
Grant/Contract Number:  
[AC05-00OR22725; FG02-98ER46544]
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
[ Journal Volume: 98; Journal Issue: 1]; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Gaudet, J, Hallas, A. M., Buhariwalla, C. R. C., Sala, Gabriele, Stone, Matthew B., Tachibana, Makoto, Baroudi, K, Cava, R. J., and Gaulin, Bruce D. Magnetoelastically induced vibronic bound state in the spin-ice pyrochlore Ho2Ti2O7. United States: N. p., 2018. Web. doi:10.1103/PhysRevB.98.014419.
Gaudet, J, Hallas, A. M., Buhariwalla, C. R. C., Sala, Gabriele, Stone, Matthew B., Tachibana, Makoto, Baroudi, K, Cava, R. J., & Gaulin, Bruce D. Magnetoelastically induced vibronic bound state in the spin-ice pyrochlore Ho2Ti2O7. United States. doi:10.1103/PhysRevB.98.014419.
Gaudet, J, Hallas, A. M., Buhariwalla, C. R. C., Sala, Gabriele, Stone, Matthew B., Tachibana, Makoto, Baroudi, K, Cava, R. J., and Gaulin, Bruce D. Thu . "Magnetoelastically induced vibronic bound state in the spin-ice pyrochlore Ho2Ti2O7". United States. doi:10.1103/PhysRevB.98.014419. https://www.osti.gov/servlets/purl/1470882.
@article{osti_1470882,
title = {Magnetoelastically induced vibronic bound state in the spin-ice pyrochlore Ho2Ti2O7},
author = {Gaudet, J and Hallas, A. M. and Buhariwalla, C. R. C. and Sala, Gabriele and Stone, Matthew B. and Tachibana, Makoto and Baroudi, K and Cava, R. J. and Gaulin, Bruce D.},
abstractNote = {The single-ion physics of Ho2Ti2O7 is well understood to produce strong Ising anisotropy, which is an essential ingredient to its low-temperature spin-ice state. We present inelastic neutron scattering measurements on Ho2Ti2O7 that reveal a clear inconsistency with its established single-ion Hamiltonian. Specifically, we show that a crystal-field doublet near 60 meV is split by approximately 3 meV. Furthermore, this crystal-field splitting is not isolated to Ho2Ti2O7 but can also be found in its chemical pressure analogs Ho2Ge2O7 and Ho2Sn2O7. We demonstrate that the origin of this effect is a vibronic bound state, resulting from the entanglement of a phonon and crystal-field excitation. In conclusion, we derive the microscopic Hamiltonian that describes the magnetoelastic coupling and provides a quantitative description of the inelastic neutron spectra.},
doi = {10.1103/PhysRevB.98.014419},
journal = {Physical Review B},
number = [1],
volume = [98],
place = {United States},
year = {2018},
month = {7}
}

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Figures / Tables:

FIG. 1 FIG. 1: (a) The CEF energy scheme for Ho2Ti2O7 deduced by Rosenkranz et al. [3], Ruminy et al. [13] and our current work. This scheme was determined via inelastic neutron scattering measurements, such as the one shown in (b), a spectrum that was collected with E$_i$ = 150 meV atmore » T = 5 K. (c) Integrated scattering from 3 to 4 Å−1, reveals a splitting of the CEF level near 60 meV in each of Ho2Ge2O7, Ho2Ti2O7, and Ho2Sn2O7. (d) Both of the excitations near 60 meV follow the magnetic form factor for Ho3+, where the intensities were extracted by fitting to the sum of two Gaussians, as depicted in (c). The temperature dependence is also consistent with a magnetic origin, as shown in the inset. (e) Our refined CEF Hamiltonian for Ho2Ti2O7 gives a good description of the experimental data, but does not capture the splitting near 60 meV. (f) The splitting can be modeled by including a magneto-elastic term in our Hamiltonian, which describes the hybridization of the CEF level with a phonon.« less

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Works referenced in this record:

Matrix Elements and Operator Equivalents Connected with the Magnetic Properties of Rare Earth Ions
journal, March 1952


XY antiferromagnetic ground state in the effective S = 1 2 pyrochlore Yb 2 Ge 2 O 7
journal, March 2016


Magnetocaloric study of spin relaxation in dipolar spin ice Dy 2 Ti 2 O 7
journal, March 2007


Chemical Pressure Effects on Pyrochlore Spin Ice
journal, May 2012


Bound State between a Crystal-Field Excitation and a Phonon in Ce Al 2
journal, November 1982


Mantid—Data analysis and visualization package for neutron scattering and μ SR experiments
journal, November 2014

  • Arnold, O.; Bilheux, J. C.; Borreguero, J. M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 764
  • DOI: 10.1016/j.nima.2014.07.029

DAVE: A Comprehensive Software Suite for the Reduction, Visualization, and Analysis of Low Energy Neutron Spectroscopic Data
journal, November 2009

  • Azuah, Richard Tumanjong; Kneller, Larry R.; Qiu, Yiming
  • Journal of Research of the National Institute of Standards and Technology, Vol. 114, Issue 6
  • DOI: 10.6028/jres.114.025

Magnetic Coulomb Phase in the Spin Ice Ho2Ti2O7
journal, September 2009


Intermediate magnetization state and competing orders in Dy2Ti2O7 and Ho2Ti2O7
journal, August 2016

  • Borzi, R. A.; Gómez Albarracín, F. A.; Rosales, H. D.
  • Nature Communications, Vol. 7, Issue 1
  • DOI: 10.1038/ncomms12592

Direct observation of magnetic monopole defects in an artificial spin-ice system
journal, April 2010

  • Ladak, S.; Read, D. E.; Perkins, G. K.
  • Nature Physics, Vol. 6, Issue 5
  • DOI: 10.1038/nphys1628

SEQUOIA: A Newly Operating Chopper Spectrometer at the SNS
journal, November 2010


Dipolar Interactions and Origin of Spin Ice in Ising Pyrochlore Magnets
journal, April 2000


The raising of angular momentum degeneracy of f-Electron terms by cubic crystal fields
journal, October 1962


Dirac Strings and Magnetic Monopoles in the Spin Ice Dy2Ti2O7
journal, September 2009


Coupling between electronic and lattice degrees of freedom in 4f-electron systems investigated by inelastic neutron scattering
journal, February 2003


Magnetic and structural instabilities in CePd2Al2 and LaPd2Al2
journal, May 2006


The Structure and Entropy of Ice and of Other Crystals with Some Randomness of Atomic Arrangement
journal, December 1935

  • Pauling, Linus
  • Journal of the American Chemical Society, Vol. 57, Issue 12
  • DOI: 10.1021/ja01315a102

Creation and measurement of long-lived magnetic monopole currents in spin ice
journal, February 2011

  • Giblin, S. R.; Bramwell, S. T.; Holdsworth, P. C. W.
  • Nature Physics, Vol. 7, Issue 3
  • DOI: 10.1038/nphys1896

Statics and dynamics of the highly correlated spin ice Ho 2 Ge 2 O 7
journal, October 2012


Theory of the bound state between phonons and a CEF excitation in CeAl 2
journal, August 1984


Magnetoelastic model for the relaxation of lanthanide ions in YBa 2 Cu 3 O 7 δ observed by neutron scattering
journal, April 2000


Dirac-Fock studies of some electronic properties of rare-earth ions
journal, May 1979


Crystal field states of Tb 3 + in the pyrochlore spin liquid Tb 2 Ti 2 O 7 from neutron spectroscopy
journal, June 2015


Treating crystal field parameters in lower than cubic symmetries
journal, January 1984


Crystal-field interaction in the pyrochlore magnet Ho2Ti2O7
journal, May 2000

  • Rosenkranz, S.; Ramirez, A. P.; Hayashi, A.
  • Journal of Applied Physics, Vol. 87, Issue 9
  • DOI: 10.1063/1.372565

Coupling of phonons to crystal-field excitations in NdBa 2 Cu 3 O 7 δ
journal, July 1991


Magnetoelastic Excitations in the Pyrochlore Spin Liquid Tb 2 Ti 2 O 7
journal, January 2014


Spin Correlations in Ho 2 Ti 2 O 7 : A Dipolar Spin Ice System
journal, July 2001


Generic quantum spin ice
journal, September 2012


Theoretical Investigation of Some Magnetic and Spectroscopic Properties of Rare-Earth Ions
journal, September 1962


Geometrical Frustration in the Ferromagnetic Pyrochlore Ho 2 Ti 2 O 7
journal, September 1997


Low temperature magnetic properties of frustrated pyrochlore ferromagnets Ho 2 Sn 2 O 7 and Ho 2 Ti 2 O 7
journal, September 2000


Vibron Quasibound State in the Noncentrosymmetric Tetragonal Heavy-Fermion Compound CeCuAl 3
journal, May 2012


Signature of magnetic monopole and Dirac string dynamics in spin ice
journal, March 2009

  • Jaubert, L. D. C.; Holdsworth, P. C. W.
  • Nature Physics, Vol. 5, Issue 4
  • DOI: 10.1038/nphys1227

Crystal electric field in the R 2 Ti 2 O 7 pyrochlore compounds
journal, May 2012


Crystal-field parameters of the rare-earth pyrochlores R 2 Ti 2 O 7 ( R = Tb , Dy, and Ho)
journal, July 2016


Single-ion anisotropy and magnetic field response in the spin-ice materials Ho 2 Ti 2 O 7 and Dy 2 Ti 2 O 7
journal, October 2015


Phonon-mediated spin-flipping mechanism in the spin ices Dy 2 Ti 2 O 7 and Ho 2 Ti 2 O 7
journal, February 2017


Coupling between crystal field transitions and phonons in the 4f-electron system CeCu2
journal, July 2003


Magnetic monopoles in spin ice
journal, January 2008

  • Castelnovo, C.; Moessner, R.; Sondhi, S. L.
  • Nature, Vol. 451, Issue 7174
  • DOI: 10.1038/nature06433

Neutron scattering study of dipolar spin ice Ho 2 Sn 2 O 7 :  Frustrated pyrochlore magnet
journal, March 2002


Neutron spectroscopic study of crystalline electric field excitations in stoichiometric and lightly stuffed Yb 2 Ti 2 O 7
journal, October 2015


Double vibronic process in the quantum spin ice candidate Tb 2 Ti 2 O 7 revealed by terahertz spectroscopy
journal, January 2017


Neutron Larmor diffraction investigation of the rare-earth pyrochlores R 2 Ti 2 O 7 ( R = Tb , Dy, Ho)
journal, November 2016


Effect of chemical pressure on the crystal electric field states of erbium pyrochlore magnets
journal, January 2018