Quantum Phases of SrCu2(BO3)2 from High-Pressure Thermodynamics
Quantum Phases of SrCu2(BO3)2 from High-Pressure Thermodynamics
复制标题
高压热力学中 SrCu2(BO3)(2) 的量子相
DOI：
10.1103/physrevlett.124.206602
复制
发表时间：
2020-05-20
影响因子：
8.6
通讯作者：
Sun, Liling
中科院分区：
文献类型：
--
作者：
Guo, Jing;Sun, Guangyu;Sun, Liling
我们报道了SrCu2(BO3)(2)在高压下的热容测量以及相关量子自旋模型的模拟，并绘制了材料的（P， T）相图。我们发现在低压量子二聚体顺磁体和在T = 2k以下具有血小板-单线态特征的相之间存在一阶量子相变。在更高的压力下，我们观察到在4k以下转变为以前未知的反铁磁状态。我们的发现可以在二维Shastry-Sutherland量子自旋模型中解释，并辅以弱层间耦合。将SrCu2(BO3)(2)调整在斑块-单线态和反铁磁态之间的可能性为量子场论和晶格模型的实验测试提供了机会，这些模型涉及分数化激发、涌现对称性和规范涨落。
We report heat capacity measurements of SrCu2(BO3)(2) under high pressure along with simulations of relevant quantum spin models and map out the (P, T) phase diagram of the material. We find a first-order quantum phase transition between the low-pressure quantum dimer paramagnet and a phase with signatures of a plaquette-singlet state below T = 2 K. At higher pressures, we observe a transition into a previously unknown antiferromagnetic state below 4 K. Our findings can be explained within the two-dimensional Shastry-Sutherland quantum spin model supplemented by weak interlayer couplings. The possibility to tune SrCu2(BO3)(2) between the plaquette-singlet and antiferromagnetic states opens opportunities for experimental tests of quantum field theories and lattice models involving fractionalized excitations, emergent symmetries, and gauge fluctuations.