Guo, JingSun, GuangyuZhao, BowenWang, LingHong, WenshanSidorov, Vladimir A.Ma, NvsenWu, QiLi, ShiliangMeng, Zi YangSandvik, Anders W.Sun, Liling2021-07-302021-07-302020-05-22Jing Guo, Guangyu Sun, Bowen Zhao, Ling Wang, Wenshan Hong, Vladimir A Sidorov, Nvsen Ma, Qi Wu, Shiliang Li, Zi Yang Meng, Anders W Sandvik, Liling Sun. 2020. "Quantum Phases of SrCu_{2}(BO_{3})_{2} from High-Pressure Thermodynamics.." Phys Rev Lett, Volume 124, Issue 20, pp. 206602 - ?. https://doi.org/10.1103/PhysRevLett.124.2066021079-7114https://hdl.handle.net/2144/42811We 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.p. 206602en-USGeneral physicsMathematical sciencesPhysical sciencesEngineeringArticle10.1103/PhysRevLett.124.2066020000-0002-5638-4619 (Sandvik, Anders W)466750