In-plane anisotropy of charge density wave fluctuations in 1$T$-TiSe${}_2$

Abstract

We report measurements of anisotropic triple-$q$ charge density wave (CDW) fluctuations in the transition metal dichalcogenide 1$T$-TiSe${}_2$ over a large volume of reciprocal space with X-ray diffuse scattering. Above the transition temperature, $T_{\text{CDW}}$, the out-of-plane diffuse scattering is characterized by rod-like structures which indicate that the CDW fluctuations in neighboring layers are largely decoupled. In addition, the in-plane diffuse scattering is marked by ellipses which reveal that the in-plane fluctuations are anisotropic. Our analysis of the diffuse scattering line shapes and orientations suggests that the three charge density wave components contain independent phase fluctuations. At $T_{\text{CDW}}$, long range coherence is established in both the in-plane and out-of-plane directions, consistent with the large observed value of the CDW gap compared to $T_{\text{CDW}}$, and the predicted presence of a hierarchy of energy scales.

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Cited by in corpus (4)

• Electron-phonon-dominated charge-density-wave fluctuations in TiSe${}_2$ accessed by ultrafast nonequilibrium dynamics
• Evolution from three-dimensional charge density wave to one-dimensional stripe order in CsV${}_{3-x}$Ti${}_x$Sb${}_5$
• Melting point depression of charge density wave in 1T-TiSe${}_2$ due to size effects
• Revisiting the charge-density-wave superlattice of 1$T$-TiSe${}_2$