Alberto Crepaldi^1*, Gabriel Autès^1,2, Gianmarco Gatti¹, Silvan Roth¹, Andrea Sterzi³, Giulia Manzoni³, Michele Zacchigna⁴, Cephice Cacho⁵, Richard T. Chapman⁵, Emma Springate⁵, Elaine A. Seddon^6,7, Philippe Bugnon¹, Arnaud Magrez¹, Helmuth Berger¹, Ivana Vobornik⁴, Matthias Kalläne⁸, Arndt Quer⁸, Kai Rossnagel⁸, Fulvio Parmigiani^3,9,10, Oleg V. Yazyev^1,2, Marco Grioni¹

1 Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

2 National Centre for Computational Design and Discovery of Novel Materials MARVEL, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

3 Università degli Studi di Trieste, Via A. Valerio 2, I-34127 Trieste, Italy

4 C.N.R.–I.O.M., Strada Statale 14, km 163.5, Trieste 34149, Italy

5 Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell OX11 0QX, United Kingdom

6 The Photon Science Institute, The University of Manchester, Manchester M13 9PL, United Kingdom

7 The Cockcroft Institute, Sci-Tech Daresbury, Daresbury, Warrington WA4 4AD, United Kingdom

8 Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany

9 Elettra - Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste 34149, Italy

10 International Faculty - University of Köln, 50937 Köln, Germany

* Corresponding authors emails: alberto.crepaldi@epfl.ch

DOI10.24435/materialscloud:ws-za [version v1]

Publication date: Apr 09, 2021

How to cite this record

Alberto Crepaldi, Gabriel Autès, Gianmarco Gatti, Silvan Roth, Andrea Sterzi, Giulia Manzoni, Michele Zacchigna, Cephice Cacho, Richard T. Chapman, Emma Springate, Elaine A. Seddon, Philippe Bugnon, Arnaud Magrez, Helmuth Berger, Ivana Vobornik, Matthias Kalläne, Arndt Quer, Kai Rossnagel, Fulvio Parmigiani, Oleg V. Yazyev, Marco Grioni, Enhanced ultrafast relaxation rate in the Weyl semimetal phase of MoTe2 measured by time- and angle-resolved photoelectron spectroscopy, Materials Cloud Archive 2021.57 (2021), doi: 10.24435/materialscloud:ws-za.

Description

This record contains the results of the first experimental investigation of the change in the electron dynamics across the topological phase transition from the type-II Weyl semimetal phase of MoTe2 to the trivial phase. By using the capability of time-resolved ARPES to access the unoccupied density of states, we succeed in transiently populating the Weyl points, which are otherwise above the Fermi level and out of the reach of conventional ARPES. We observe a bottleneck in the electron dynamics when the Weyl points annihilate and gaps are opened in the high-temperature trivial phase. This interpretation is supported by the observation that, in the “sister” compound WTe2 the dynamics is not affected by the change in temperature, and it is always much slower, thus reflecting the larger energy separation between the valence and conduction band.

Materials Cloud sections using this data

Files

File name	Size	Description
Data.zip MD5md5:354f8269654de7738953fcc85cec59b7	3.9 MiB	Compressed folder containing the data, divided in folders according to the Figure panels as described in the README file.
README.txt MD5md5:e48c3108537994157722bef5abdb91ae	1.3 KiB	Information about how the data have been exported in .txt and how to fully reconstruct the raw data.

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External references

Keywords

Electronic bands Electron dynamics Type-II Weyl semimetal Topological phase transition Experimental SNSF MARVEL ERC