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arXiv · 2505.00766

Novel bipartite entanglement in the quantum dimer magnet Yb$_2$Be$_2$SiO$_7$

A. Brassington·Q. Ma·G. Duan·S. Calder·A. I. Kolesnikov·K. M. Taddei·G. Sala·E. S. Choi·H. Wang·W. Xie·B. A. Frandsen·N. Li·X. F. Sun·C. Liu·R. Yu·H. D. Zhou·A. A. Aczel
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Abstract

The quantum dimer magnet, with antiferromagnetic intradimer and interdimer Heisenberg exchange between spin-1/2 moments, is known to host an up/down - down/up singlet ground state when the intradimer exchange is dominant. Rare-earth-based quantum dimer systems with strong spin-orbit coupling offer the opportunity for tuning their magnetic properties by using magnetic anisotropy as a control knob. Here, we present bulk characterization and neutron scattering measurements of the quantum dimer magnet Yb$_2$Be$_2$SiO$_7$. We find that the Yb$^{3+}$ ions can be described by an effective spin-1/2 model at low temperatures and the system does not show signs of magnetic order down to 50 mK. The magnetization, heat capacity, and neutron spectroscopy data can be well-described by an isolated dimer model with highly anisotropic exchange that stabilizes a singlet ground state with a wavefunction up/up - down/down or up/up + down/down. Our results show that strong spin-orbit coupling can induce novel entangled states of matter in quantum dimer magnets.

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A. Brassington, Q. Ma, G. Duan, S. Calder, A. I. Kolesnikov, K. M. Taddei, G. Sala, E. S. Choi, H. Wang, W. Xie, B. A. Frandsen, N. Li, X. F. Sun, C. Liu, R. Yu, H. D. Zhou, A. A. Aczel. 2025-05-01. Novel bipartite entanglement in the quantum dimer magnet Yb$_2$Be$_2$SiO$_7$. https://arxiv.org/abs/2505.00766

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