Doping Dependent Evolution of the Fermi Surface and Competing Ordering Phenomena in Superconduction Cuprates

对费米面的大小和拓扑的详细了解以及它随掺杂的演变是理解铜酸盐超导体物理的关键因素。到目前为止，有关费米表面的信息主要是从表面敏感的ARPES实验中获得的，受到表面极化和自掺杂效应的影响。幸运的是，单晶的质量已经提高到一定程度，第一次能够观察到磁量子振荡(舒布尼科夫·德·哈斯和德哈斯-范·阿尔芬效应)。这为一类全新的实验打开了可能性，提供了关于铜酸盐超导体体电性质的非常理想的信息。这一提议的主要目的是通过磁量子振荡的方法，详细和系统地研究各种铜酸盐超导体的费米面的大小和拓扑，以及它随掺杂的演变。我们的实验是基于超清洁的单晶，最近成功地展示了对其磁量子振荡的观测。它们有望为铜酸盐超导体中超导电性的起源和有序竞争现象提供新的有价值的信息。

The detailed knowledge of the size and topology of the Fermi surface as well as its evolution with doping is a key ingredient for understanding the physics of the cuprate superconductors. So far, information on the Fermi surface has been mostly obtained from surface-sensitive ARPES experiments, suffering from surface polarization and self-doping effects. Fortunately, the quality of single crystals has been improved to a level, allowing for the first time for the observation of magnetic quantum oscillations (Shubnikovde Haas and de Haas-van Alphen effect). This opened up the possibility for a completely new class of experiments, providing the highly desired information on the bulk electronic properties of cuprate superconductors. The key goal of this proposal is the detailed and systematic study of the size and topology of the Fermi surface of various cuprate superconductors as well as its evolution with doping by means of magnetic quantum oscillations. Our experiments are based on ultra-clean single crystals, for which the observation of magnetic quantum oscillations has been successfully demonstrated very recently. They are expected to provide new and valuable information on the origin of superconductivity and competing ordering phenomena in the cuprate superconductors.