论文标题
群集模型中的新兴相位转变
Emergent phase transition in Cluster Ising model with dissipation
论文作者
论文摘要
我们研究了具有非热场外场的群集模型，该模型可以用自由费米子的语言来解决。通过研究能量密度和保真度的第二个导数，可能的新临界点是暂定位置的。然后检测到弦顺序参数和交错磁化，以揭示全新特征的新兴阶段。为了对非热性引起的外来相和相变类进行分类，我们计算自旋相关函数的变化模式以及字符串参数，这些模式表征了具有不同衰减和关键指数模式的新兴相位和临界点。借助弦顺序参数和交错的磁化，我们发现引入非热度之后有四个阶段 - 聚类相，无间隙相，顺磁性（PM）相和抗铁磁（AF）相。然后，基于两个“ KT样”相变和一个ISING相变的相位图以图形方式说明，随着非赫米特强度的提高，三个临界线的产生。预计我们的理论工作将在超冷原子的实验中实现，从而促进了探索新型相和相变的进步。
We study a cluster Ising model with non-Hermitian external field which can be exactly solved in the language of free fermions. By investigating the second derivative of energy density and fidelity, the possible new critical points are tentatively located. String order parameter and staggered magnetization are then detected to reveal emergent phases of brand new characteristics. To categorize the exotic phases and phase transitions induced by non-Hermiticity, we calculate the variation mode of spin correlation function as well as string parameter, which characterize the emergent phases and critical points with different patterns of decay and critical exponents. With the help of string order parameter and staggered magnetization, we find that there are four phases after introducing the non-Hermiticity -- the cluster phase, the gapless phase, the paramagnetic (PM) phase and the antiferromagnetic (AF) phase. A phase diagram is then presented to graphically illustrate, based on two "KT-like" phase transitions and an Ising phase transition, respectively, the generation of three critical lines as non-Hermitian strength increases. Our theoretical work is expected to be realized in the experiment of ultra-cold atoms, pushing for progress in exploring novel phases and phase transitions.
