4.6 Article

Single monkey-saddle singularity of a Fermi surface and its instabilities

期刊

PHYSICAL REVIEW B
卷 107, 期 20, 页码 -

出版社

AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.107.205129

关键词

-

向作者/读者索取更多资源

Fermi surfaces can undergo sharp transitions with topological character when higher-order singularities develop at the transition. Odd singularities appear in pairs within the Brillouin zone when time-reversal and inversion symmetries are present. The combination of enhanced density of states and nesting between the singularities leads to interaction-driven instabilities.
Fermi surfaces can undergo sharp transitions under smooth changes of parameters. Such transitions can have a topological character, as is the case when a higher-order singularity, one that requires cubic or higher-order terms to describe the electronic dispersion near the singularity, develops at the transition. When time-reversal and inversion symmetries are present, odd singularities can only appear in pairs within the Brillouin zone. In this case, the combination of the enhanced density of states that accompanies these singularities and the nesting between the pairs of singularities leads to interaction-driven instabilities. We present examples of single n = 3 (monkeysaddle) singularities when time-reversal and inversion symmetries are broken. We then turn to the question of what instabilities are possible when the singularities are isolated. For spinful electrons, we find that the inclusion of repulsive interactions destroys any isolated monkey-saddle singularity present in the noninteracting spectrum by developing Stoner or Lifshitz instabilities. In contrast, for spinless electrons and at the mean-field level, we show that an isolated monkey-saddle singularity can be stabilized in the presence of short-range repulsive interactions.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据