Motivated by the novel phenomena observed in the layered material SrCu2(BO3)2, the Shastry-Sutherland model (SSM) has been extensively studied as the minimal model for SrCu2(BO3)2. However, the nature of its quantum phase transition from the plaquette valence-bond solid (PVBS) to antiferromagnetic (AFM) phase is under fierce debate, posing a challenge to understand the underlying quantum criticality. Via the state-of-the-art tensor network simulations, we study the ground state of the SSM on large-scale size up to 20×20 sites. We identify the continuous transition nature accompanied by an emergent O(4) symmetry between the PVBS and AFM phase, which strongly suggests a deconfined quantum critical point (DQCP). Furthermore, we map out the phase diagram of an extended SSM that can be continuously tuned to the SSM, which demonstrates the same DQCP phenomena along a whole critical line. Our results indicate a compelling scenario for understanding the origin of the proposed proximate DQCP in recent experiments of SrCu2(BO3)2.
@article{arxiv.2309.10955,
title = {Quantum criticality with emergent symmetry in the extended Shastry-Sutherland model},
author = {Wen-Yuan Liu and Xiao-Tian Zhang and Zhe Wang and Shou-Shu Gong and Wei-Qiang Chen and Zheng-Cheng Gu},
journal= {arXiv preprint arXiv:2309.10955},
year = {2024}
}