%0 journal article
%@ 0027-8424
%A Scheie, A., Kindervater, J., Zhang, S., Changlani, H., Sala, G., Ehlers, G., Heinemann, A., Tucker, G., Koohpayeh, S., Broholm, C.

%D 2020
%J Proceedings of the National Academy of Sciences of the United States of America: PNAS
%N 44
%P 27245-27254 
%R doi:10.1073/pnas.2008791117
%T Multiphase magnetism in Yb2Ti2O7
%U https://doi.org/10.1073/pnas.2008791117
44 
%X 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.