Charge order -- ubiquitous among correlated materials -- is customarily described purely as an instability of the electronic structure. However, the resulting theoretical predictions often do not match high-resolution experimental data. A pertinent case is $1T$-VSe$_2$, whose single-band Fermi surface and weak-coupling nature make it qualitatively similar to the Peierls model underlying the traditional approach. Despite this, its Fermi surface is poorly nested, the thermal evolution of its charge density wave (CDW) ordering vectors displays an unexpected jump, and the CDW gap itself evades detection in direct probes of the electronic structure. We demonstrate that the thermal variation of the CDW vectors is naturally reproduced by the electronic susceptibility when incorporating a structured, momentum-dependent electron-phonon coupling, while the evasive CDW gap presents itself as a localized suppression of spectral weight centered above the Fermi level. Our results showcase the general utility of incorporating a structured coupling in the description of charge ordered materials, including those that appear unconventional.

中文翻译：

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VSe $ _2 $中来自结构化耦合的收费订单

通常在相关材料中无处不在的电荷顺序通常被纯粹描述为电子结构的不稳定性。但是，所得的理论预测通常与高分辨率的实验数据不符。一个相关的案例是$ 1T $ -VSe $ _2 $，其单频带费米表面和弱耦合特性使其在质量上与传统方法的Peierls模型相似。尽管如此，其费米表面嵌套不良，其电荷密度波（CDW）有序向量的热演化显示出意外的跃变，并且CDW间隙本身在电子结构的直接探针中规避了检测。我们证明，当结合结构化的，依赖于动量的电子-声子耦合时，CDW向量的热变化可以自然地通过电子磁化率再现，而逃避的CDW间隙则表现为以费米能级为中心的频谱权重的局部抑制。我们的结果表明，在有偿订购材料的描述中包括结构化耦合的通用性，包括那些看起来非常规的材料。