Proximate deconfined quantum critical point in SrCu2(BO3)2

• 成果类型: Article
• 署名作者: Cui, Yi; Liu, Lu; Lin, Huihang; Wu, Kai-Hsin; Hong, Wenshan; Liu, Xuefei; Li, Cong; Hu, Ze; Xi, Ning; Li, Shiliang; Yu, Rong; Sandvik, Anders W.; Yu, Weiqiang
• 署名单位: Renmin University of China; Chinese Academy of Sciences; Beijing Institute of Technology; Boston University; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Songshan Lake Materials Laboratory; Renmin University of China
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-11293
• DOI: 10.1126/science.adc9487
• 发表日期: 2023-06-16
• 页码: 1179-1184
• 关键词: dimer ground-state; singlet-state; MODEL

摘要

The deconfined quantum critical point (DQCP) represents a paradigm shift in quantum matter studies, presenting a beyond Landau scenario for order-order transitions. Its experimental realization, however, has remained elusive. Using high-pressure 11B nuclear magnetic resonance measurements on the quantum magnet SrCu2(BO3)2, we here demonstrate a magnetic field- induced plaquette singlet to antiferromagnetic transition above 1.8 gigapascals at a notably low temperature, Tc similar or equal to 0.07 kelvin. First-order signatures of the transition weaken with increasing pressure, and we observe quantum critical scaling at the highest pressure, 2.4 gigapascals. Supported by model calculations, we suggest that these observations can be explained by a proximate DQCP inducing critical quantum fluctuations and emergent O(3) symmetry of the order parameters. Our findings offer a concrete experimental platform for investigation of the DQCP.