Scholarlink

<p>Exploiting electronic singularities to drive emergent quantum phenomena is a key basis in condensed matter physics, yet this powerful strategy has been largely limited to two dimensions, leaving the potential of three-dimensional materials often inaccessible. A “saddle-loop” singularity—a one-dimensional ring of saddle points—has been proposed as a way to extend the concept of van Hove singularities to three-dimensional electron systems, but has remained experimentally elusive. Here, we provide the direct experimental evidence for the saddle‑loop singularity in Pt(Bi<sub>1−<i>x</i></sub>Se<sub><i>x</i></sub>)<sub>2</sub>, using angle‑resolved photoemission spectroscopy. We also show that the saddle loop is positioned closer to the Fermi level at low <i>x</i> values where the superconducting critical temperature is higher. Furthermore, our advanced theoretical calculations reveal that the saddle loop originates from inter-orbital hybridization, establishing a generalizable design concept. Our findings demonstrate a viable mechanism for realizing singular electronic states in three-dimensional electron systems, providing a platform to investigate correlation-driven phenomena in three dimensions.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Observation of a saddle-loop van Hove singularity

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年6月25日

查看全文
  • Y. Morita,
  • K. Nakayama,
  • N. Ito,
  • T. Kato,
  • T. Nakamura,
  • H. Zhang,
  • X. Tang,
  • T. Lin,
  • K. Yanagizawa,
  • S. Souma,
  • S. Masaki,
  • T. Ikushima,
  • Y. Moriyasu,
  • K. Hagiwara,
  • F. Matsui,
  • K. Tanaka,
  • K. Ozawa,
  • D. Shiga,
  • H. Kumigashira,
  • M. Maeda,
  • Y. Niimi,
  • T. Kida,
  • M. Hagiwara,
  • T. K. Kim,
  • C. Cacho,
  • T. Takahashi,
  • Y. Okada,
  • S. Zhou,
  • T. Koretsune,
  • K. Kudo,
  • T. Sato

摘要

Exploiting electronic singularities to drive emergent quantum phenomena is a key basis in condensed matter physics, yet this powerful strategy has been largely limited to two dimensions, leaving the potential of three-dimensional materials often inaccessible. A “saddle-loop” singularity—a one-dimensional ring of saddle points—has been proposed as a way to extend the concept of van Hove singularities to three-dimensional electron systems, but has remained experimentally elusive. Here, we provide the direct experimental evidence for the saddle‑loop singularity in Pt(Bi1−xSex)2, using angle‑resolved photoemission spectroscopy. We also show that the saddle loop is positioned closer to the Fermi level at low x values where the superconducting critical temperature is higher. Furthermore, our advanced theoretical calculations reveal that the saddle loop originates from inter-orbital hybridization, establishing a generalizable design concept. Our findings demonstrate a viable mechanism for realizing singular electronic states in three-dimensional electron systems, providing a platform to investigate correlation-driven phenomena in three dimensions.