Disordered Route to the Coulomb Quantum Spin Liquid: Random Transverse Fields on Spin Ice in Pr_{2}Zr_{2}O_{7}

J-J Wen; S M Koohpayeh; K A Ross; B A Trump; T M McQueen; K Kimura; S Nakatsuji; Y Qiu; D M Pajerowski; J R D Copley; C L Broholm

doi:10.1103/PhysRevLett.118.107206

Disordered Route to the Coulomb Quantum Spin Liquid: Random Transverse Fields on Spin Ice in Pr_{2}Zr_{2}O_{7}

Phys Rev Lett. 2017 Mar 10;118(10):107206. doi: 10.1103/PhysRevLett.118.107206. Epub 2017 Mar 8.

Authors

J-J Wen^{1

2

3}, S M Koohpayeh¹, K A Ross^{1

4}, B A Trump⁵, T M McQueen^{1

5

6}, K Kimura^{7

8}, S Nakatsuji^{7

9}, Y Qiu⁴, D M Pajerowski⁴, J R D Copley⁴, C L Broholm^{1

4

6}

Affiliations

¹ Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
² Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
³ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
⁴ NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
⁵ Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
⁶ Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
⁷ Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
⁸ Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
⁹ CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.

PMID: 28339241
DOI: 10.1103/PhysRevLett.118.107206

Abstract

Inelastic neutron scattering reveals a broad continuum of excitations in Pr_{2}Zr_{2}O_{7}, the temperature and magnetic field dependence of which indicate a continuous distribution of quenched transverse fields (Δ) acting on the non-Kramers Pr^{3+} crystal field ground state doublets. Spin-ice correlations are apparent within 0.2 meV of the Zeeman energy. A random phase approximation provides an excellent account of the data with a transverse field distribution ρ(Δ)∝(Δ^{2}+Γ^{2})^{-1}, where Γ=0.27(1) meV. Established during high temperature synthesis due to an underlying structural instability, it appears disorder in Pr_{2}Zr_{2}O_{7} actually induces a quantum spin liquid.