Candidate for a quantum spin liquid ground state in the Shastry-Sutherland lattice material <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Yb</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Be</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>GeO</mml:mi><mml:mn>7</mml:mn></mml:msub></mml:mrow></mml:math>
M. Pula, S. Sharma, J. Gautreau, K. P. Sajilesh, Amit Kanigel, M. D. Frontzek, Tristan N. Dolling, Luther T. Clark, S. R. Dunsiger, A. Ghara, G. M. Luke
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 ${\mathrm{SrCu}}_{2}{({\mathrm{BO}}_{3})}_{2}$. 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, ${\mathrm{Yb}}_{2}{\mathrm{Be}}_{2}{\mathrm{GeO}}_{7}$, of the rare-earth melilite family ${\mathrm{RE}}_{2}{\mathrm{Be}}_{2}{\mathrm{GeO}}_{7}$. We find, through SQUID magnetometry, powder neutron diffraction, specific heat capacity, and muon spin relaxation, that ${\mathrm{Yb}}_{2}{\mathrm{Be}}_{2}{\mathrm{GeO}}_{7}$ lacks magnetic order and exhibits persistent spin dynamics to at least 17 mK. We propose the Shastry-Sutherland lattice material ${\mathrm{Yb}}_{2}{\mathrm{Be}}_{2}{\mathrm{GeO}}_{7}$ as a candidate to host a quantum spin liquid ground state.