论文标题
田间诱导的手性孤子相位
Field Induced Chiral Soliton Phase in the Kitaev Spin Chain
论文作者
论文摘要
Kitaev模型中存在的债券依赖性ISINT相互作用引起了很大的关注。在磁场下出现意外的中间阶段的出现特别吸引人，并且可能怀疑在Kitaev旋转链中是否发生了类似的阶段，交替的$ x $ - 和$ y $ $ $ - bond Ising Isestions。先前的研究集中在横向场，$ H_z $，并报告了直接过渡到两极分化状态。在这里，我们研究了两个纵向场，$ h_x $和$ h_y $的任意角度的阶段。对于沿对角线应用的磁场，$ h_x $ = $ h_y $，链条保持无间隙至关键场$ h^{c_1} _ {xy} $。令人惊讶的是，上面$ h^{c1} _ {xy} $它进入了一个不寻常的中间阶段，然后以$ h^{c_2} _ {xy} $到达偏光状态。该阶段的特征是交错的矢量性手性和周期性边界条件，这是有限间隙的两倍变性。对于开放的边界系统，基态表现出单个孤子，降低了能量和无间隙激发。然而，相应的反索顿充分提高了能量，以使周期系统中的孤子和反索顿对出现差距。开发了描述孤子阶段的直观变分图。
The bond-dependent Ising interaction present in the Kitaev model has attracted considerable attention. The appearance of an unexpected intermediate phase under a magnetic field is particularly intriguing, and one may wonder if a similar phase occurs in the Kitaev spin chain with alternating $x$- and $y$-bond Ising interactions. Previous studies have focused on a transverse field, $h_z$, and reported a direct transition to the polarized state. Here, we investigate phases with arbitrary angle of two longitudinal fields, $h_x$ and $h_y$. For a magnetic field applied along the diagonal, $h_x$=$h_y$, the chain remains gapless up to a critical field $h^{c_1}_{xy}$. Surprisingly, above $h^{c1}_{xy}$ it enters an unusual intermediate phase before reaching the polarized state at $h^{c_2}_{xy}$. This phase is characterized by a staggered vector chirality and for periodic boundary conditions, a two-fold degeneracy with a finite gap. For open boundary systems the ground-state exhibits a single soliton, lowering the energy, and gapless excitations. However, the corresponding anti-soliton raises the energy sufficiently that a gap appears for soliton and anti-soliton pairs in periodic systems. An intuitive variational picture is developed describing the soliton phase.
