论文标题
来自磁弹性耦合的单极物质
Monopole matter from magnetoelastic coupling in the Ising pyrochlore
论文作者
论文摘要
pyrochlore氧化物晶格上的ISING模型通常与自旋冰材料和“磁性单极”有关。在这些和其他相关的沮丧材料上报告了连接磁性和弹性自由度的经常影响。在这里，我们扩展了一个自旋冰冰哈密顿量，包括旋转和o $^{ - 2} $ ions介导superexchange之间的耦合；我们称其为磁弹性自旋冰模型（MESI）。人们已经很长时间搜索了一个模型，在这种模型中，单孔会自发地成为新地面的基础：Mesi Hamiltonian就是这样的模型。尽管它具有简单性和经典方法，但它描述了（旋转和氧晶格）在TB $ _2 $ _2 $ _2 $ _2 $ o $ $ _7 $中观察到的双层单极晶体。值得注意的是，单个单极的偶极电矩作为磁性探针出现。作为一个例子，我们表明，与o $^{ - 2} $离子位移有关，可以检测到与库仑相关的捏点。
Ising models on a pyrochlore oxide lattice are usually associated with spin ice materials and "magnetic monopoles". Ever more often effects connecting magnetic and elastic degrees of freedom are reported on these and other related frustrated materials. Here we extend a spin-ice Hamiltonian to include coupling between spins and the O$^{-2}$ ions mediating superexchange; we call it the Magnetoelastic Spin Ice model (MeSI). There has been a long search for a model in which monopoles would spontaneously become the building blocks of new ground-states: the MeSI Hamiltonian is such a model. In spite of its simplicity and classical approach, it describes (both spin and oxygen lattice) the double-layered monopole crystal observed in Tb$_2$Ti$_2$O$_7$. Remarkably, the dipolar electric moment of single monopoles emerges as a probe for magnetism. As an example we show that, in principle, pinch points related to Coulomb phases could be detected in association with the O$^{-2}$-ion displacements.
