论文标题
磁场引起沮丧的反铁磁铁cav $ _4 $ o $ $ _9 $的三重动力激发中的拓扑结节线
Magnetic field induced topological nodal-lines in triplet excitations of frustrated antiferromagnet CaV$_4$O$_9$
论文作者
论文摘要
磁场诱导的多个非迪拉克节点线被发现在Cavo晶格上沮丧的Spin-1/2抗磁模型的三胞胎分散带中出现。在存在基于plaquette-resonation-valence-bond和dimerized地面状态的情况下，plaquette and Bond运算符的形式主义已被用来获得两个不同参数制度的三重态plaquette和键盘激发。在没有磁场的情况下，一对具有不同拓扑特征的六倍退化的结节环在plaquette激发中注意到。在磁场存在的情况下，发现它们分为三对两倍变化的节点环。在另一个参数状态下，系统在磁场存在的情况下，在三分法分散带中具有两倍的脱位多个节点线，并具有各种形状。基态能量和自旋差距已针对这两个方案进行了额外的确定。预计这些节点线在沮丧的抗铁磁铁上的中子散射实验中可检测到，cav $ _4 $ o $ _9 $。
Magnetic field induced multiple non-Dirac nodal-lines are found to emerge in the triplet dispersion bands of a frustrated spin-1/2 antiferromagnetic model on the CaVO lattice. Plaquette and bond operator formalisms have been employed to obtain the triplet plaquette and bond excitations for two different parameter regimes in the presence of nearest and next-nearest-neighbor Heisenberg interactions based on the plaquette-resonating-valence-bond and dimerized ground states, respectively. In the absence of magnetic field a pair of six-fold degenerate nodal-loops with distinct topological feature is noted in the plaquette excitations. They are found to split into three pairs of two-fold degenerate nodal-loops in the presence of magnetic field. In the other parameter regime, system hosts two-fold degenerate multiple nodal-lines with a variety of shapes in the triplon dispersion bands in the presence of magnetic field. Ground state energy and spin gap have been determined additionally for the two regimes. Those nodal-lines are expected to be detectable in neutron scattering experiment on the frustrated antiferromagnet, CaV$_4$O$_9$.
