Spin-spin correlations in Yb2Ti2O7:: A polarized neutron scattering study -: art. no. 180404

Polarized neutron diffraction and neutron spin echo have been employed to investigate the low-temperature (T<2 K) magnetic correlations in the frustrated magnet Yb2Ti2O7. Several studies have reported a phase transition at 240 mK, however, the low-temperature phase is still under debate. It has been reported that Yb2Ti2O7 enters a frozen ferromagnetic phase, however, studies of the spin dynamics suggest otherwise. Our results conclusively rule out a frozen ferromagnetic state and confirm that the majority of the spin system continues to fluctuate below 240 mK.