title: Low-temperature low-field phases of the pyrochlore quantum magnet Tb2Ti2O7.
abstract: By means of ac magnetic-susceptibility measurements, we find evidence for a new magnetic phase of Tb2Ti2O7 below about 140 mK in zero magnetic field. In magnetic fields parallel to [111], this phase is characterized by frequency- and amplitude-dependent susceptibility and extremely slow spin dynamics. In the zero-temperature limit, it extends to about 67 mT (the internal field H(int)≃52  mT), at which it makes transition to another phase. The field dependence of the susceptibility of this second phase, which extends to about 0.60 T (H(int)≃0.54  T) in the zero-temperature limit, indicates the presence of a weak magnetization plateau below about 50 mK, as has been predicted by a single-tetrahedron four-spin model, suggesting that the second phase is a quantum kagome ice.
authors.affiliation: National High Magnetic Field Laboratory and Department of Physics, University of Florida, Gainesville, Florida 32611, USA. yin@phys.ufl.edu
authors.forename: L
authors.initials: L
authors.lastname: Yin
authors.forename: J S
authors.initials: JS
authors.lastname: Xia
authors.forename: Y
authors.initials: Y
authors.lastname: Takano
authors.forename: N S
authors.initials: NS
authors.lastname: Sullivan
authors.forename: Q J
authors.initials: QJ
authors.lastname: Li
authors.forename: X F
authors.initials: XF
authors.lastname: Sun