标题： 基于Jeff = 1/2的受挫三角晶格反铁磁体的磁基态 显示英文标题

标题： Magnetic ground state of a Jeff = 1/2 based frustrated triangular lattice antiferromagnet

摘要： 在竞争性自由度、晶体电场和自旋关联之间的微妙相互作用可能导致基于4f离子的挫败磁体中的奇异量子态。我们对基于4f离子的挫败磁体Ba4YbReWO12进行了晶体结构、热力学和μ子自旋弛豫研究，其中Yb3+离子构成三角晶格。磁化率在1.9 K以下没有自旋冻结的迹象，或在0.4 K以下没有长程磁序的迹象。低温下逆磁化率的Curie-Weiss拟合显示，Yb3+磁矩最低Kramers双线态中的Jeff=1/2态之间存在微弱的反铁磁交换相互作用。最低Kramers基态双线态与第一激发态之间有278 K的能隙，这通过μ子自旋弛豫实验得到证实，这些实验支持在低温下实现Jeff 1/2态。比热表明在0.09 K处发生相变，低温下的相关熵释放与Jeff = 1/2态预期的熵释放一致。零场μSR测量在至少43 mK以下既没有自旋冻结的迹象，也没有相变的迹象。我们的结果表明，在这个Jeff = 1/2的挫败三角晶格反铁磁体的基态中，静态和缓慢波动的磁矩共存。Ba4RReWO12（R=稀土元素）提供了一个可行的平台，以实现由自旋-轨道耦合和挫败产生的有趣量子态。 显示英文摘要

摘要： The subtle interplay between competing degrees of freedom, crystal electric fields, and spin correlations can lead to exotic quantum states in 4f ion-based frustrated magnets. We present the crystal structure, thermodynamic, and muon spin relaxation studies of the 4f ion-based frustrated magnet Ba4YbReWO12, wherein Yb3+ ions constitute a triangular lattice. The magnetic susceptibility does not show any signature of spin freezing down to 1.9 K or long-range magnetic ordering down to 0.4 K. The low-temperature Curie-Weiss fit to the inverse magnetic susceptibility data reveals a weak antiferromagnetic exchange interaction between the Jeff=1/2 state of the Yb3+ moments in the lowest Kramers doublet. The lowest Kramers ground state doublet is well separated from the first excited state with a gap of 278 K, as evidenced by our muon spin relaxation experiments that support the realization of the Jeff 1/2 state at low temperatures. The specific heat indicates a phase transition at 0.09 K, and the associated entropy release at low temperatures is consistent with that expected for the Jeff = 1/2 state. The zero-field muSR measurements show neither the signature of spin freezing nor a phase transition, at least down to 43 mK. Our results suggest the coexistence of static and slowly fluctuating moments in the ground state of this Jeff = 1/2 frustrated triangular lattice antiferromagnet. Ba4RReWO12 (R=rare earth) offers a viable platform to realize intriguing quantum states borne out of spin-orbit coupling and frustration.