EMP is funded through the Horizon2020 programme of the European Commission.
Selected Publications

First-order magnetic transition in Yb2Ti2O7

R. Sibille, E. Lhotel, T. Mazet, B. Malaman, C. Ritter, V. Ban, and M. Francois

The very nature of the ground state of the pyrochlore compound Yb2Ti2O7 is much debated, because experimental results demonstrate evidence for either a disordered ground state or a long-range ordered ground state. Indeed, the delicate balance of exchange interactions and anisotropy is believed to lead to competing states, such as a quantum spin liquid state or a ferromagnetic state which may originate from an Anderson-Higgs transition. We present a detailed magnetization study demonstrating a first-order ferromagnetic transition at 245 and 150 mK in a powder and a single-crystal sample, respectively. Its first-order character is preserved up to applied fields of ∼200 Oe. The transition stabilizes a ferromagnetic component and involves slow dynamics in the magnetization. Residual fluctuations are also evidenced, the presence of which might explain some of the discrepancies between previously published data for Yb2Ti2O7.

Phys. Rev. B 89, 224419 (2014)

doi: 10.1103/PhysRevB.89.224419