标题： 宇称-时间对称非厄米哈密顿量中的Kondo效应 显示英文标题

标题： Kondo effect in a parity-time-symmetric non-Hermitian Hamiltonian

摘要： 非厄米物理与强关联的结合可以在具有平衡增益和损耗的开放量子多体系统中产生新的效应。 我们提出了一种广义的安德森杂质模型，该模型包括嵌入量子点与两条导线之间的非厄米跃迁项。 这些非厄米跃迁项尊重宇称-时间（$\mathcal{PT}$）对称性。 在单占据局域态的区域，我们将问题映射到一个$\mathcal{PT}$对称的Kondo模型，并使用微扰重整化群方法研究相互作用的影响。 我们发现，如果耦合低于对应于非厄米Kondo相互作用的奇异点的临界值，Kondo效应仍然存在。 另一方面，在自发破缺$\mathcal{PT}$对称性的区域，Kondo效应被抑制，低能性质由一个局域磁矩固定点主导，其电导为零。 显示英文摘要

摘要： The combination of non-Hermitian physics and strong correlations can give rise to new effects in open quantum many-body systems with balanced gain and loss. We propose a generalized Anderson impurity model that includes non-Hermitian hopping terms between an embedded quantum dot and two wires. These non-Hermitian hopping terms respect a parity-time ($\mathcal{PT}$) symmetry. In the regime of a singly occupied localized state, we map the problem to a $\mathcal{PT}$-symmetric Kondo model and study the effects of the interactions using a perturbative renormalization group approach. We find that the Kondo effect persists if the couplings are below a critical value that corresponds to an exceptional point of the non-Hermitian Kondo interaction. On the other hand, in the regime of spontaneously broken $\mathcal{PT}$ symmetry, the Kondo effect is suppressed and the low-energy properties are governed by a local-moment fixed point with vanishing conductance.