基于增广多极子的多轨道超导态分类
Classification of multiorbital superconducting state based on augmented multipoles
AI总结：
本文将多极子表示扩展到南部空间，在晶体学点群下将任意角动量的库珀对系统分为电、磁、磁环和电环四类多极子，并以sp轨道系统为例验证，为多轨道非常规超导态提供了统一分类框架。
摘要：
电子之间的配对相互作用在决定超导态性质方面起着至关重要的作用。近年来，大量非常规超导态得到了广泛探索，这些超导态通常因多极序附近的多极涨落而出现。我们通过将多极子的表示扩展到南部空间，从多极子自由度的角度对这些超导态进行分类。我们阐明，在晶体学点群下，具有任意角动量的电子之间形成的任意库珀对可以系统地分为四类多极子：电极、磁极、磁环极和电环极。作为例子，我们将我们的公式应用于一个 $sp$ 轨道电子系统，该系统在极性和轴性点群下可能展现出奇异的库珀对。我们的系统分类将有助于表征多轨道系统中的非常规超导态。
英文摘要：
The pairing interactions between electrons play an essential role in determining the properties in superconducting states. Recently, a plethora of unconventional superconducting states has been extensively explored, which often emerge owing to multipole fluctuations in the vicinity of multipole orders. We classify such superconducting states from the viewpoint of the multipole degrees of freedom by extending its representation to Nambu space. We clarify that under the crystallographic point group, arbitrary Cooper pairs between electrons with any angular momenta are systematically classified by four types of multipoles: electric, magnetic, magnetic toroidal, and electric toroidal. As examples, we apply our formulation to an $sp$-orbital electron system, which potentially exhibits exotic Cooper pairs under polar and axial point groups. Our systematic classification will be useful in characterizing unconventional superconducting states in multiorbital systems.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
