论文标题
动量空间中的假想仪转换和迪拉克特殊点
Imaginary gauge transformation in momentum space and Dirac exceptional point
论文作者
论文摘要
假想的仪表转换是非铁皮皮肤效应的核心。在这里，我们表明，这种转换也可以在动量空间中进行，这表明其平等时代（PT）对称阶段的某些增益和损失调制系统等同于具有真实潜力的Hermitian系统。我们在动量空间中的分析还区分了同一系统中两种类型的特殊点（EP）。除了在收益和损失持续增加时导致PT过渡的常规类型外，我们还发现在混合维度的Dirac EP上连接的实价值，包括空间维度和合成维度的增益和损耗强度。
An imaginary gauge transformation is at the core of the non-Hermitian skin effect. Here we show that such a transformation can be performed in momentum space as well, which reveals that certain gain and loss modulated systems in their parity-time (PT) symmetric phases are equivalent to Hermitian systems with real potentials. Our analysis in momentum space also distinguishes two types of exceptional points (EPs) in the same system. Besides the conventional type that leads to a PT transition upon the continuous increase of gain and loss, we find real-valued energy bands connected at a Dirac EP in hybrid dimensions, consisting of a spatial dimension and a synthetic dimension for the gain and loss strength.
