Candidate for a quantum spin liquid ground state in the Shastry-Sutherland lattice material Yb2⁢Be2⁢GeO7

Abstract

The quasi-two-dimensional Shastry-Sutherland model has remained topical in the field of condensed matter physics for the last two decades, following the experimental realization of the model in the material SrCu2⁢(BO3)2. Since then, research into the Shastry-Sutherland system has revealed more nuanced physics than initially predicted; recent theoretical works have even predicted a quantum spin liquid phase may exist. Herein, we report on a new Shastry-Sutherland lattice material, Yb2⁢Be2⁢GeO7, of the rare-earth melilite family RE2⁢Be2⁢GeO7. We find, through SQUID magnetometry, powder neutron diffraction, specific heat capacity, and muon spin relaxation, that Yb2⁢Be2⁢GeO7 lacks magnetic order and exhibits persistent spin dynamics to at least 17 mK. We propose the Shastry-Sutherland lattice material Yb2⁢Be2⁢GeO7 as a candidate to host a quantum spin liquid ground state.