Vibrating-coil magnetometry of the spin liquid properties of Tb2Ti2O7

TL;DR

This study investigates the spin liquid state in Tb2Ti2O7 using vibrating coil magnetometry at very low temperatures, revealing magnetic history dependence and an isotropic phase diagram consistent with all-in/all-out antiferromagnetism rather than quantum spin ice behavior.

Contribution

It provides new experimental evidence on the magnetic properties of Tb2Ti2O7, challenging the quantum spin ice model and suggesting a spin liquid state related to AIAO antiferromagnetism.

Findings

Magnetic history dependence observed below 0.2 K.

Isotropic phase diagram without magnetization plateaux.

Magnetization aligns with AIAO antiferromagnetic predictions.

Abstract

We have explored the spin liquid state in Tb2Ti2O7 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 Ho2Ti2O7 and Dy2Ti2O7. The magnetic phase diagram inferred from the magnetization is essentially isotropic, without evidence of magnetization plateaux as anticipated for so-called quantum spin ice, predicted theoretically for [111] when quantum fluctuations renormalize the interactions. Instead, the magnetization for $T \ll T*$ agrees semi-quantitatively with the predictions of "all-in/all-out" (AIAO) antiferromagnetism. Taken together this suggests that the spin liquid state in Tb2Ti2O7 is akin to an incipient AIAO-antiferromagnet.