Magnetic excitations in the ground state of Yb2Ti2O7

Journal article

We report an extensive study on the zero field ground state of a powder sample of the pyrochlore Yb 2 Ti 2 O 7 . A sharp heat capacity anomaly that labels a low temperature phase transition in this material is observed at 280 mK. Neutron diffraction shows that a quasicollinear ferromagnetic order develops below Tc with a magnetic moment of 0.87(2)μB. High resolution inelastic neutron scattering measurements show, below the phase transition temperature, sharp gapped low-lying magnetic excitations coexisting with a remnant quasielastic contribution likely associated with persistent spin fluctuations. Moreover, a broad inelastic continuum of excitations at ∼0.6 meV is observed from the lowest measured temperature up to at least 2.5 K. At 10 K, the continuum has vanished and a broad quasielastic conventional paramagnetic scattering takes place at the observed energy range. Finally, we show that the exchange parameters obtained within the framework of linear spin-wave theory do not accurately describe the observed zero field inelastic neutron scattering data.

Authors: Peçanha-Antonio, V; Feng, E; Su, Y; Pomjakushin, V; Demmel, F

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: APS Physics
• Journal: Phyisical Review B
• Volume: 96
• Issue: 21
• Publication date: 2017-12-11
• DOI: 10.1103/PhysRevB.96.214415
• ISSN: 2469-9950
• Keywords: FFR