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Updated: Aug 14, 2026
09:23
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
Floquet topological state induced by light-driven band inversion in SnTe
F Chassot1, A Pulkkinen2, G Kremer3
1Department of Physics and Fribourg Center for Nanomaterials, Université de Fribourg, Fribourg, Switzerland.
Nature Physics
|August 13, 2026
Summary
Researchers created a transient Floquet topological state in SnTe using femtosecond light pulses. This light-induced topological phase, absent in equilibrium, demonstrates optical control over semiconductor topological properties.
Area of Science:
- Condensed matter physics
- Quantum materials
- Semiconductor physics
Background:
- High-intensity coherent light can engineer exotic quantum states of matter.
- Floquet engineering, using periodic electric fields, modifies electronic band structures and can induce topological phases.
- Experimental realization of Floquet topological insulators in semiconductors remains a challenge.
Purpose of the Study:
- To experimentally realize and observe a Floquet topological state in a semiconductor.
- To investigate the possibility of creating non-equilibrium topological phases using light pulses.
- To demonstrate optical control over topological properties in semiconductors.
Main Methods:
- Photo-excitation of SnTe using femtosecond light pulses with energy near the bandgap.
- Spectroscopic observation of band renormalization and Floquet state generation.
- Analysis of the induced topological state and its connection to band inversion.
Main Results:
- A short-lived topological state, absent in the equilibrium ground state, was created in SnTe.
- Femtosecond light pulses induced a renormalization of band dispersions, revealing Floquet states.
- Evidence suggests the topological state is driven by a light-induced band inversion in SnTe.
Conclusions:
- Direct experimental observation of a Floquet topological state in a semiconductor has been achieved.
- Femtosecond light pulses can dynamically induce topological phases in SnTe.
- Optical control of topological properties in semiconductors is a viable prospect.
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