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 Yb2Be2SiO7. We find that the Yb3+ 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.
@article{arxiv.2505.00766,
title = {Novel bipartite entanglement in the quantum dimer magnet Yb$_2$Be$_2$SiO$_7$},
author = {A. Brassington and Q. Ma and G. Duan and S. Calder and A. I. Kolesnikov and K. M. Taddei and G. Sala and E. S. Choi and H. Wang and W. Xie and B. A. Frandsen and N. Li and X. F. Sun and C. Liu and R. Yu and H. D. Zhou and A. A. Aczel},
journal= {arXiv preprint arXiv:2505.00766},
year = {2025}
}