Proximate deconfined quantum critical point in SrCu2(BO3)2
Proximate deconfined quantum critical point in SrCu2(BO3)2
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DOI：
10.1126/science.adc9487
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发表时间：
2022-04
期刊：
影响因子：
56.9
通讯作者：
Yi Cui;Lu Liu;Hui-Yu Lin;Kai-Hsin Wu;Wenshan Hong;Xuefei Liu;Congjian Li;Ze Hu;N. Xi;Shiliang Li;R. Yu;A. Sandvik;Weiqiang Yu
中科院分区：
文献类型：
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作者：
Yi Cui;Lu Liu;Hui-Yu Lin;Kai-Hsin Wu;Wenshan Hong;Xuefei Liu;Congjian Li;Ze Hu;N. Xi;Shiliang Li;R. Yu;A. Sandvik;Weiqiang Yu
去受限量子临界点(DQCP)代表了量子物质研究中的一种范式转变，为有序-有序转变提供了一种“超越朗道”的场景。然而，它的实验实现仍然难以捉摸。利用量子磁体SrCu2(BO_3)_2的高压~(11)B核磁共振测量，我们证明了磁场诱导的斑块单态在1.8千兆卡以上的反铁磁跃迁，温度非常低，TC≃为0.07Kelvin。跃迁的一阶特征随压强的增加而减弱，我们在最高压强下观察到量子临界标度，最高压强为2.4千兆。在模型计算的支持下，我们认为这些观测可以用DQCP引起的临界量子涨落和有序参数的突现O(3)对称性来解释。我们的发现为DQCP的研究提供了一个具体的实验平台。描述编辑的摘要具有不相关对称性的阶段之间的过渡应该是不连续的。近二十年前，人们提出了一种不同的、连续的这种相之间的转变，命名为去受限量子临界点(DQCP)。然而，在实验上观察DQCP已被证明是极具挑战性的。崔等人。利用核磁共振研究了层状材料SrCu2(BO3)2在不同压力下的磁场驱动相变。在高压下，实验结果与数值计算相结合，表明附近存在DQCP。-Jelena Stajic核磁共振用于研究层状材料SrCu2(BO3)2的磁场驱动相变。
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 ≃ 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. Description Editor’s summary Transitions between phases with unrelated symmetries are expected to be discontinuous. Nearly two decades ago, a different, continuous kind of transition between such phases was proposed under the name deconfined quantum critical point (DQCP). However, observing the DQCP experimentally has proven to be extremely challenging. Cui et al. used nuclear magnetic resonance to study the magnetic field–driven transitions of the layered material SrCu2(BO3)2 at various pressures. At high pressures, the experimental results combined with numerical calculations pointed to the existence of a nearby DQCP. —Jelena Stajic Nuclear magnetic resonance is used to study the magnetic field–driven transitions of the layered material SrCu2(BO3)2.