Observation of Dirac Charge Density Waves in Bi2Te2Se

Adrian Ruckhofer, Giorgio Benedek, Martin Bremholm, Wolfgang E. Ernst, Anton Tamtögl

Research output: Contribution to journalArticlepeer-review


While parallel segments in the Fermi level contours, often found at the surfaces of topological insulators (TIs) would imply ”strong” nesting conditions, the existence of charge density waves (CDWs) - periodic modulations of the electron density - has not been verified up to now. Here, we report the observation of a CDW at the surface of the TI Bi2Te2Se(111), below ≈ 350 K by helium atom scattering, and thus experimental evidence for a CDW involving Dirac topological electrons. Deviations of the order parameter observed below 180 K and a low temperature break of time reversal symmetry suggest the onset of a spin density wave with the same period as the CDW in presence of a prominent electron-phonon interaction originating from the Rashba spin-orbit coupling.
Original languageEnglish
Article number476
Issue number3
Publication statusPublished - 24 Jan 2023

Fields of Expertise

  • Advanced Materials Science


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