Scholarlink

<p>High-intensity coherent light can realize hybrid phases of matter that are not accessible in equilibrium. The coherent interaction between Bloch states and a periodic electric field, which leads to Floquet-engineered band structures, has been extensively discussed in the literature and shown to enable modified electronic states, and it potentially induces topological phases in semiconductors. However, a Floquet topological insulator has not yet been realized experimentally in a semiconductor. Here we show that femtosecond light pulses can create a short-lived topological state in SnTe that is absent from the equilibrium ground state. This occurs when the photo-excitation energy is close to the bandgap of this polar semiconductor. We observe a concomitant renormalization of the band dispersions that reveals the generation of Floquet states connected to the topological state. These results provide a direct experimental observation of a Floquet topological state and indicate that it is driven by a light-induced band inversion in SnTe, although further theoretical work will provide a more detailed characterization of the state. Our work also indicates that optical control of the topological properties of semiconductors on demand is possible.</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

Floquet topological state induced by light-driven band inversion in SnTe

  • 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
  • F. Chassot,
  • A. Pulkkinen,
  • G. Kremer,
  • C. Wang,
  • J. Schusser,
  • J. Krempaský,
  • J. Minár,
  • G. Springholz,
  • M. Puppin,
  • J. H. Dil,
  • C. Monney

摘要

High-intensity coherent light can realize hybrid phases of matter that are not accessible in equilibrium. The coherent interaction between Bloch states and a periodic electric field, which leads to Floquet-engineered band structures, has been extensively discussed in the literature and shown to enable modified electronic states, and it potentially induces topological phases in semiconductors. However, a Floquet topological insulator has not yet been realized experimentally in a semiconductor. Here we show that femtosecond light pulses can create a short-lived topological state in SnTe that is absent from the equilibrium ground state. This occurs when the photo-excitation energy is close to the bandgap of this polar semiconductor. We observe a concomitant renormalization of the band dispersions that reveals the generation of Floquet states connected to the topological state. These results provide a direct experimental observation of a Floquet topological state and indicate that it is driven by a light-induced band inversion in SnTe, although further theoretical work will provide a more detailed characterization of the state. Our work also indicates that optical control of the topological properties of semiconductors on demand is possible.