论文标题

近红色效果,$ \ nathcal {pt} $ - 对称的安德森模型,带有rashba旋转轨道耦合

Kondo effect in a non-Hermitian, $\mathcal{PT}$-symmetric Anderson model with Rashba spin-orbit coupling

论文作者

Kulkarni, Vinayak M, Gupta, Amit, Vidhyadhiraja, N. S.

论文摘要

非相互作用和非热的,平等的时间($ \ Mathcal {pt} $) - 对称的Anderson模型在非铁偶联$ g = 1 $上表现出异常点(EP),在交互作用的情况下保持不明显(Lourenco等人,Arxiv:18006.033116) (QCP)用于围to毁灭性。在这项工作中,我们考虑了带有Rashba旋转轨耦合($λ$)的金属铅的量子点杂交。我们表明,对于非热杂交,$λ$即使在非相互作用的情况下也可以重新归一致,稳定$ \ Mathcal {pt} $ - 超过$ g = 1 $。 Through exact diagonalization of a zero-bandwidth, three-site model, we show that the quantum critical point and the exceptional point bifurcate, with the critical point for Kondo destruction at $g_c=1$, and the exceptional coupling being $g_{\scriptscriptstyle{EP}} > 1$ for all $U\neq 0$ and $λ\geq 0; λ\ neq u/2 $。在行$λ= u/2 $上,关键点和EP再次重合为$ g_c = g _ {\ scriptScriptStryle {ep}}} = 1 $。通过奴隶玻璃孔方法研究了具有有限带宽线索的完整模型,我们使用该方法表明,在强耦合方案中,$λ$和Interactions合作以强烈降低与Kondo Destruction相关的临界点,低于$λ= 0 $值。

The non-interacting and non-Hermitian, parity-time ($\mathcal{PT}$)-symmetric Anderson model exhibits an exceptional point (EP) at a non-Hermitian coupling $g=1$, which remains unrenormalized in the presence of interactions (Lourenco et al, arXiv:1806.03116), where the EP was shown to coincide with the quantum critical point (QCP) for Kondo destruction. In this work, we consider a quantum dot hybridizing with metallic leads having Rashba spin-orbit coupling ($λ$). We show that for a non-Hermitian hybridization, $λ$ can renormalize the exceptional point even in the non-interacting case, stabilizing $\mathcal{PT}$-symmetry beyond $g=1$. Through exact diagonalization of a zero-bandwidth, three-site model, we show that the quantum critical point and the exceptional point bifurcate, with the critical point for Kondo destruction at $g_c=1$, and the exceptional coupling being $g_{\scriptscriptstyle{EP}} > 1$ for all $U\neq 0$ and $λ\geq 0; λ\neq U/2$. On the line $λ=U/2$, the critical point and the EP again coincide at $g_c=g_{\scriptscriptstyle{EP}}=1$. The full model with finite bandwidth leads is investigated through the slave-boson approach, using which we show that, in the strong coupling regime, $λ$ and interactions co-operate in strongly reducing the critical point associated with Kondo destruction, below the $λ=0$ value.

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