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arXiv · 1901.07819

Transient Hot Electron Dynamics in Single-Layer TaS$_2$

Federico Andreatta·Habib Rostami·Antonija Grubišić Čabo·Marco Bianchi·Charlotte E. Sanders·Deepnarayan Biswas·Cephise Cacho·Alfred J. H. Jones·Richard T. Chapman·Emma Springate·Phil D. C. King·Jill A. Miwa·Alexander Balatsky·Søren Ulstrup·Philip Hofmann
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Abstract

Using time- and angle-resolved photoemission spectroscopy, we study the response of metallic single layer TaS$_2$ in the 1H structural modification to the generation of excited carriers by a femtosecond laser pulse. A complex interplay of band structure modifications and electronic temperature increase is observed and analyzed by direct fits of model spectral functions to the two-dimensional (energy and $k$-dependent) photoemission data. Upon excitation, the partially occupied valence band is found to shift to higher binding energies by up to 150 meV, accompanied by electronic temperatures exceeding 3000~K. These observations are explained by a combination of temperature-induced shifts of the chemical potential, as well as temperature-induced changes in static screening. Both contributions are evaluated in a semi-empirical tight-binding model. The shift resulting from a change in the chemical potential is found to be dominant.

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Federico Andreatta, Habib Rostami, Antonija Grubišić Čabo, Marco Bianchi, Charlotte E. Sanders, Deepnarayan Biswas, Cephise Cacho, Alfred J. H. Jones, Richard T. Chapman, Emma Springate, Phil D. C. King, Jill A. Miwa, Alexander Balatsky, Søren Ulstrup, Philip Hofmann. 2019-01-23. Transient Hot Electron Dynamics in Single-Layer TaS$_2$. https://doi.org/10.1103/physrevb.99.165421

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