标题： 非厄米系统中的零间接带隙 显示英文标题

标题： Zero Indirect Band Gap in Non-Hermitian Systems

摘要： 非间接带隙在能带模型中通常被视为不稳定，并且只能通过精细调节实现。 最近的研究却发现，在厄米系统中存在稳定的半金属相，其中间接带隙在有限的参数范围内保持为零。 在此，我们通过研究一个具有增益和损耗的一维类金刚石系统，将这一范式扩展到非厄米格点模型。 我们表明，零间接带隙可以抵抗非厄米扰动并确定这种鲁棒性持续存在的区域。 值得注意的是，我们发现零间接带隙会引发一种与文献中已讨论的其他物理机制不同的非厄米皮肤效应抑制。 我们的结果揭示了间接带隙、例外点和非厄米皮肤效应之间的新联系，为实验实现开辟了新的途径。 显示英文摘要

摘要： Zero indirect gaps in band models are typically viewed as unstable and achievable only through fine-tuning. Recent works, however, have revealed robust semimetallic phases in Hermitian systems where the indirect gap remains pinned at zero over a finite parameter range. Here, we extend this paradigm to non-Hermitian lattice models by studying a one-dimensional diamond-like system with gain and loss. We show that a zero indirect band gap can remain stable against non-Hermitian perturbations and identify the regimes where this robustness persists. Remarkably, we find that the zero indirect gap induces a suppression of the non-Hermitian skin effect distinct from other physical mechanics already discussed in the literature. Our results reveal new connections between indirect gaps, exceptional points and non-Hermitian skin effect, opening avenues for experimental realizations.