Ultrafast Dynamics of Charge Density Waves in4Hb−TaSe2Probed by Femtosecond Electron Diffraction

2012/09/03 by N. Erasmus, Nicolas Erasmus, M. Eichberger +9 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Charge (physics) #Charge density wave #Charge ordering #Condensed matter physics #Diffraction #Femtosecond #Laser #Materials science #Optics #Order (exchange) #Organic and Molecular Conductors Research #Perovskite Materials and Applications #Phase (matter) #Phase transition #Physics #Quantum mechanics #cond-mat.mtrl-sci #cond-mat.str-el

paper · pdf · doi:10.1103/physrevlett.109.167402

5 pages, 3 figures, accepted for publication in Phys. Rev. Lett

arxiv created 2012/09/03 · openalex publication_date 2012/10/18 · arxiv updated 2015/06/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The dynamics of the photoinduced commensurate-to-incommensurate charge density wave (CDW) phase transition in 4H(b)-TaSe(2) are investigated by femtosecond electron diffraction. In the perturbative regime, the CDW re-forms on a 150-ps time scale, which is two orders of magnitude slower than in other transition-metal dichalcogenides. We attribute this to a weak coupling between the CDW carrying T layers and thus demonstrate the importance of three-dimensionality for the existence of CDWs. With increasing optical excitation, the phase transition is achieved, showing a second-order character, in contrast to the first-order behavior in thermal equilibrium.

Citations

• Femtosecond data storage, processing, and search using collective excitations of a macroscopic quantum state
• Fermi surface nesting and the origin of charge density waves in metals
• Femtosecond snapshots of gap-forming charge-density-wave correlations in quasi-two-dimensional dichalcogenides1T−TaS2and2H−TaSe2

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