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arXiv · 2002.07896

Concurrent probing of electron-lattice dephasing induced by photoexcitation in 1T-TaSeTe using ultrafast electron diffraction

Jun Li·Junjie Li·Kai Sun·Lijun Wu·Renkai Li·Jie Yang·Xiaozhe Shen·Xijie Wang·Huixia Luo·Robert J. Cava·Ian K. Robinson·Xilian Jin·Weiguo Yin·Yimei Zhu·Jing Tao
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Abstract

It has been technically challenging to concurrently probe the electrons and the lattices in materials during non-equilibrium processes, allowing their correlations to be determined. Here, in a single set of ultrafast electron diffraction patterns taken on the charge-density-wave (CDW) material 1T-TaSeTe, we discover a temporal shift in the diffraction intensity measurements as a function of scattering angle. With the help of dynamic models and theoretical calculations, we show that the ultrafast electrons probe both the valence-electron and lattice dynamic processes, resulting in the temporal shift measurements. Our results demonstrate unambiguously that the CDW is not merely a result of the periodic lattice deformation ever-present in 1T-TaSeTe but has significant electronic origin. This method demonstrates a novel approach for studying many quantum effects that arise from electron-lattice dephasing in molecules and crystals for next-generation devices.

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Jun Li, Junjie Li, Kai Sun, Lijun Wu, Renkai Li, Jie Yang, Xiaozhe Shen, Xijie Wang, Huixia Luo, Robert J. Cava, Ian K. Robinson, Xilian Jin, Weiguo Yin, Yimei Zhu, Jing Tao. 2020-02-18. Concurrent probing of electron-lattice dephasing induced by photoexcitation in 1T-TaSeTe using ultrafast electron diffraction. https://doi.org/10.1103/physrevb.101.100304

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