论文标题
在具有远距离相互作用的抗铁磁旋转梯子的拓扑至磁性量子相变
Topological to magnetically ordered quantum phase transition in antiferromagnetic spin ladders with long-range interactions
论文作者
论文摘要
我们研究了具有交错的远距离相互作用的广义量子自旋梯子，它们是指数$α$的幂律。使用大型量子蒙特卡洛（QMC）和密度矩阵重新归一化组（DMRG）模拟，我们表明该模型从以非局部字符串阶参数为特征的rung-dimer相的过渡到对称性的破碎Néel相位。我们发现过渡是二阶的证据。在磁有序的相中，频谱表现出无间隙模式，而间隙相中的激发在三倍的方面得到很好的描述 - 跨腿的纺纱子的结合状态。我们从数值上获得了动量解析的自旋动态结构因子，并找到了一个定义明确的三位龙带，该带状循环在整个过渡过程中演变成无间隙的木剂分散体。我们进一步讨论了在该模型中解除批判性的可能性。
We study a generalized quantum spin ladder with staggered long range interactions that decay as a power-law with exponent $α$. Using large scale quantum Monte Carlo (QMC) and density matrix renormalization group (DMRG) simulations, we show that this model undergoes a transition from a rung-dimer phase characterized by a non-local string order parameter, to a symmetry broken Néel phase. We find evidence that the transition is second order. In the magnetically ordered phase, the spectrum exhibits gapless modes, while excitations in the gapped phase are well described in terms of triplons -- bound states of spinons across the legs. We obtain the momentum resolved spin dynamic structure factor numerically and find a well defined triplon band that evolves into a gapless magnon dispersion across the transition. We further discuss the possibility of deconfined criticality in this model.
