$$μ$$ $$\mathrm{SR}$$ study of the dipole-octupole quantum spin ice candidate $$\mathrm{Ce_2Zr_2O_7}$$

Journal Article · 07 November 2023 · Physical Review. B

DOI: https://doi.org/10.1103/physrevb.108.174411 · OSTI ID:2251582

Beare, James  ^[1]; Smith, Evan M.  ^[1]; Dudemaine, J. ^[2]; Schäfer, R. ^[3]; Rutherford, M. R. ^[1]; Sharma, Sudarshan  ^[1]; Fitterman, A. ^[2]; Marjerrison, C. A. ^[1]; Williams, T. J. ^[4]; Aczel, Adam A.  ^[4]; Dunsiger, S. R. ^[5]; Bianchi, Andrea D.  ^[2]; Gaulin, Bruce D.  ^[6]; Luke, Graeme M.  ^[7]

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1. McMaster Univ., Hamilton, ON (Canada)
2. Univ. of Montreal, QC (Canada)
3. Boston Univ., MA (United States)
4. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
5. Simon Fraser Univ., Burnaby, BC (Canada); TRIUMF, Vancouver, BC (Canada)
6. McMaster Univ., Hamilton, ON (Canada); Canadian Institute for Advanced Research (CIFAR), Toronto, ON (Canada)
7. McMaster Univ., Hamilton, ON (Canada); TRIUMF, Vancouver, BC (Canada)

The Ce³⁺ pseudospin-1/2 degrees of freedom in Ce₂Zr₂O₇ possess both dipolar and octupolar character which enables the possibility of novel quantum spin liquid ground states in this material. In this study, we report muon spin relaxation and rotation (μSR) measurements on single-crystal samples of Ce₂Zr₂O₇ in zero magnetic field and in magnetic fields directed along the [1, $$\overline{1}$$, 0] and [1, 1, 1] crystallographic directions, and for magnetic fields directed both longitudinal and transverse to the direction of muon polarization. Our zero-field results show no signs of magnetic ordering or spin freezing, consistent with earlier zero-field μSR measurements on a powder sample of Ce₂Zr₂O₇, and also with the expectations for a quantum spin ice. However, we measure a more gentle relaxation rate for Ce₂Zr₂O₇ in zero field at low temperatures than was previously reported. This difference in relaxation rate is likely due to the low oxidation and, correspondingly, the high stoichiometry of our singlecrystal samples. Longitudinal field measurements confirm that the magnetic dipole moments in Ce₂Zr₂O₇ remain dynamic at T = 0.1 K on the microsecond timescale. For both [1, $$\overline{1}$$, 0] and [1, 1, 1] magnetic fields, our μSR Knight shift measurements show a field-induced leveling off of the magnetic susceptibility at low temperature which is qualitatively consistent with corresponding calculations using the numerical-linked-cluster method in combination with recent estimates for the nearest-neighbor exchange parameters of Ce₂Zr₂O₇.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); US Air Force Office of Scientific Research (AFOSR)
• Grant/Contract Number: AC05-00OR22725; FA 9550-20-1-0235
• OSTI ID: 2251582
• Journal Information: Physical Review. B, Vol. 108, Issue 17; ISSN 2469-9950
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English