论文标题
在自旋玻色子模型中出现的量子三位点点，在交错偏见中有两个耗散旋转
Quantum tricritical point emerging in the spin-boson model with two dissipative spins in staggered biases
论文作者
论文摘要
我们通过基于变异矩阵乘积状态的数值精确方法研究了带有两个交错偏见的自旋玻色子模型（SBM）。精确计算了几种可观察的东西，例如磁化强度，两个自旋与骨骼环境之间的纠缠熵，地面能量以及两个自旋的相关函数。这些可观察到的特征表明，交错的偏见可以将二阶量子相变（QPT）驱动到亚霍米克SBM中的一阶QPT，而ohmic SBM中的kosterlitz-thouless qpt直接进入一阶。然后可以检测到连续QPT符合一阶的量子三位点点。发现交错的偏见不会改变量子三智度下方的{该模型中的相变的普遍性。
We study the spin-boson model (SBM) with two spins in staggered biases by a numerically exact method based on variational matrix product states. Several observables such as the magnetization, the entanglement entropy between the two spins and the bosonic environment, the ground-state energy, as well as the correlation function for two spins are calculated exactly. The characteristics of these observables suggest that the staggered biases can drive the 2nd-order quantum phase transition (QPT) to the 1st-order QPT in the sub-Ohmic SBM, while the Kosterlitz-Thouless QPT in the Ohmic SBM goes directly to the 1st-order one. A quantum tricritical point, where the continuous QPT meets the 1st-order one, can then be detected. It is found that the staggered biases would not change the universality of { the phase transition in this model} below the quantum tricritical point.
