Scholarlink

<p>Chirality generates striking quantum responses even in light-element materials. However, the real-space picture connecting crystal chirality to electronic topology through chemical bonding has remained elusive. Here we directly visualize the chiral bonding network responsible for multifold topological fermions by combining synchrotron X-ray diffraction and first-principles calculations on cubic chiral crystals, CoSi and FeSi. Based on observations of asymmetric valence electron distributions, together with bonding analyses, we develop a three-dimensional Su-Schrieffer-Heeger model, showing that inter-site hopping on this chiral network creates multifold fermions with doubled topological invariants. We demonstrate that topological features can be controlled through two distinct routes: crystalline chirality reversal and electron filling, the latter switching the bonding/antibonding character while maintaining crystal structure. This bonding-driven mechanism operates at eV-scale energies without requiring spin-orbit coupling, enabling robust topological phases at elevated temperatures. Moreover, this real-space framework naturally extends to other elementary excitations or metamaterials, enabling quantum functionalities through chirality engineering.</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

Unraveling a chemical-bond-driven root of topology in three-dimensional chiral crystals

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月30日

查看全文
  • Shungo Aoyagi,
  • Shunsuke Kitou,
  • Yuiga Nakamura,
  • Motoaki Hirayama,
  • Hideki Matsuoka,
  • Ryotaro Arita,
  • Shuichi Murakami,
  • Taka-hisa Arima,
  • Naoya Kanazawa

摘要

Chirality generates striking quantum responses even in light-element materials. However, the real-space picture connecting crystal chirality to electronic topology through chemical bonding has remained elusive. Here we directly visualize the chiral bonding network responsible for multifold topological fermions by combining synchrotron X-ray diffraction and first-principles calculations on cubic chiral crystals, CoSi and FeSi. Based on observations of asymmetric valence electron distributions, together with bonding analyses, we develop a three-dimensional Su-Schrieffer-Heeger model, showing that inter-site hopping on this chiral network creates multifold fermions with doubled topological invariants. We demonstrate that topological features can be controlled through two distinct routes: crystalline chirality reversal and electron filling, the latter switching the bonding/antibonding character while maintaining crystal structure. This bonding-driven mechanism operates at eV-scale energies without requiring spin-orbit coupling, enabling robust topological phases at elevated temperatures. Moreover, this real-space framework naturally extends to other elementary excitations or metamaterials, enabling quantum functionalities through chirality engineering.