Field induced ground states in Tb₂Ti₂O₇ spin liquid

We have studied the field induced magnetic structures (H//[110]) in Tb2Ti2O7 in a wide temperature (0.2<T<270 K) and field (0<H<7 T) range, by combining polarized and unpolarized neutron diffraction in a single crystal. Below 2 K and above 2 T, two structures with k 0 and (0,0,1) propagation vectors are simultaneously observed. Their analysis yields a precise description of the field induced ground states. The k 0 structure with net magnetization shows spin-ice like local order, but with Tb moments of very different magnitudes. The k (0,0,1) AF-like structure is stabilized in a finite (H,T) range and attributed to magnetostriction.