论文标题
在野战中的抗磁量子质量链中的混合顺序转变
Mixed-order transition in the antiferromagnetic quantum Ising chain in a field
论文作者
论文摘要
抗铁磁量子iSing链具有一个量子临界点，该点属于横向iSing模型的通用类别（TIM）。当打开一个纵向场（$ h $）时，将保留相变，该相变为$ h/γ\ to \ infty $的一阶，$γ$是横向场的强度。在这里，我们将重新检查沿相变线的关键特性。在量子块重新归一化组计算过程中，发现$ H/γ> 0 $的TIM固定点不稳定。使用DMRG技术，我们计算了纠缠熵和自旋旋转相关函数，这两者都表明了与TIM指数的过渡点处的不同相关长度。同时，批量相关函数具有跳跃，并且端到端相关函数在过渡点具有不连续的导数。因此，对于有限的$ h/γ$，过渡是混合订单。
The antiferromagnetic quantum Ising chain has a quantum critical point which belongs to the universality class of the transverse Ising model (TIM). When a longitudinal field ($h$) is switched on, the phase transition is preserved, which turns to first-order for $h/Γ\to \infty$, $Γ$ being the strength of the transverse field. Here we will re-examine the critical properties along the phase transition line. During a quantum block renormalization group calculation, the TIM fixed point for $h/Γ>0$ is found to be unstable. Using DMRG techniques, we calculated the entanglement entropy and the spin-spin correlation function, both of which signaled a divergent correlation length at the transition point with the TIM exponents. At the same time, the bulk correlation function has a jump and the end-to-end correlation function has a discontinuous derivative at the transition point. Consequently for finite $h/Γ$ the transition is of mixed-order.
