Multiphase magnetism in Yb 2 Ti 2 O 7

We use neutron scattering to show that ferromagnetism and antiferromagnetism coexist in the low T state of the pyrochlore quantum magnet$Yb2Ti2O7$. 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$⟨111⟩$-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$Yb2Ti2O7$is a consequence of this multiphase magnetism.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
NSF-PAR ID:
10199102
Journal Name:
Proceedings of the National Academy of Sciences
Volume:
117
Issue:
44
Page Range or eLocation-ID:
p. 27245-27254
ISSN:
0027-8424
Publisher:
Proceedings of the National Academy of Sciences
National Science Foundation
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