Vibrating-coil magnetometry of the spin liquid properties of Tb2Ti2O7.

We have explored the spin liquid state in Tb(2)Ti(2)O(7) with vibrating-coil magnetometry down to 0.04 K under magnetic fields up to 5 T. We observe magnetic history dependence below T*0.2 K reminiscent of the classical spin ice systems Ho(2)Ti(2)O(7) and Dy(2)TiTi(2)O(7). The magnetic phase diagram inferred from the magnetization is essentially isotropic, without evidence of magnetization plateaus as anticipated for so-called quantum spin ice, predicted theoretically for [111] when quantum fluctuations renormalize the interactions. Instead, the magnetization for T≪T* agrees semiquantitatively with the predictions of "all-in-all-out" (AIAO) antiferromagnetism. Taken together, this suggests that the spin liquid state in Tb(2)Ti(2)O(7) is akin to an incipient AIAO antiferromagnet.