Interplay between the charge densitiy waves and superconductivity in transition metal chalcogenides

固体中的密度波是价电子自组织的一个迷人的例子，它导致材料物理性质的显着改变。在铜氧化物和新型铁超导体中，电荷和自旋密度波及其涨落是否是高温超导不可缺少的因素，目前正处于激烈的争论之中。我们的结果在前面的建议的框架内得到的强烈建议，虽然在最具代表性的硫属元素和其他化合物的电荷密度波的起源是有关的电子结构的嵌套不稳定性，电子有序本身对超导电性是重要的。本建议的目的是澄清CDW和超导电性之间相互作用的起源，并将已发展的方法扩展到超导电性。利用现代ARPES及其与其他技术的结合，在低临界转变温度的硫属化合物的相图中，各种材料特有的问题，如掺杂TaSe 2中狄拉克锥的形成或NbSe 2中预测的振幅模式的检测也将得到解决。

The density waves in solids are a fascinating example of the self-organization of the valence electronswhich leads to significant modifications of the physical properties of the material. It is currentlyunder intense debates whether the charge and/or spin-density waves and their fluctuationsare indispensable ingredients for the high-temperature superconductivity in the cuprates and novelFe-superconductors. Our results obtained within the framework of the previous proposal stronglysuggest that while the origin of the charge-density waves in the most representative chalcogenidesand other compounds is related to the nesting instability of the electronic structure, the electronicorder itself is important for the superconductivity.The aim of this proposal is to clarify the origin of the interplay between CDW and superconductivityand to extend the developed approach to the phase diagrams of the chalcogenides with lowcritical transition temperatures using modern ARPES and its combination with other techniques.At this, a variety of material-specific issues, such as formation of the Dirac cones in doped TaSe2or detection of the predicted amplitude mode in NbSe2 will be addressed as well.