Multiphase magnetism in Yb <sub>2</sub> Ti <sub>2</sub> O <sub>7</sub>
Allen Scheie, J. Kindervater, Shu Zhang, Hitesh J. Changlani, Gabriele Sala, G. Ehlers, A. Heinemann, G. S. Tucker, S. M. Koohpayeh, C. Broholm
Abstract
We use neutron scattering to show that ferromagnetism and antiferromagnetism coexist in the low T state of the pyrochlore quantum magnet [Formula: see text] 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 [Formula: see text]-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 [Formula: see text] is a consequence of this multiphase magnetism.