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arXiv · 2412.17913

Quantum entanglement of XY-type spin dimers in Shastry-Sutherland lattice

Qianli Ma·Brianna R. Billingsley·Madalynn Marshall·David A. Dahlbom·Yiqing Hao·Daniel M. Pajerowski·Alexander I. Kolesnikov·Xiaojian Bai·Cristian D. Batista·Tai Kong·Huibo Cao
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Abstract

We report a comprehensive study on the origin of the enigmatic disordered ground state within the Shastry-Sutherland lattice, BaCe$_2$ZnS$_5$, at low temperatures. The magnetization and heat capacity data show a lack of magnetic ordering down to 73 mK. We deploy a localized spin dimer model which can accurately reproduce the dynamic structure factor of the neutron data, magnetization and heat capacity data. Remarkably, the intra-dimer exchange interaction shows strong XY-type anisotropy and the ground state of BaCe$_2$ZnS$_5$ is in an entangled state $(|\uparrow\uparrow> - |\downarrow\downarrow>)/\sqrt{2}$. This is in contrast to the singlet dimer state that is obtained for Heisenberg interactions. These results confirm that BaCe$_2$ZnS$_5$ is in a quantum paramagnet state consisting of entangled spin dimer states.

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Qianli Ma, Brianna R. Billingsley, Madalynn Marshall, David A. Dahlbom, Yiqing Hao, Daniel M. Pajerowski, Alexander I. Kolesnikov, Xiaojian Bai, Cristian D. Batista, Tai Kong, Huibo Cao. 2024-12-23. Quantum entanglement of XY-type spin dimers in Shastry-Sutherland lattice. https://doi.org/10.1103/gl65-17z7

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