Max Burian¹, Michael Porer¹, Jose R.L. Mardegan^1,2, Vincent Esposito^1,3, Sergii Parchenko^1,4, Burganov Bulat⁵, Namrata Gurung^4,6, Mahesh Ramakrishnan¹, Valerio Scagnoli^4,6, Hirkoi Ueda¹, Sonia Francoual², Federica Fabrizi⁷, Yoshikazu Tanaka⁸, Tadashi Togashi^8,9, Kai Rossnagel^10,11, Steven L. Johnson^5,12, Urs Staub^1*

1 Swiss Light Source, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland

2 Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany

3 Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA

4 Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zürich, Switzerland

5 Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, 8093 Zürich, Switzerland

6 Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland

7 Diamond Light Source Ltd., Didcot, Oxfordshire OX11 0DE, United Kingdom

8 RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan

9 Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan

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

11 Ruprecht-Haensel-Labor, Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg, Germany

12 SwissFEL, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland

* Corresponding authors emails: urs.staub@psi.ch

DOI10.24435/materialscloud:b3-e5 [version v1]

Publication date: Jan 27, 2021

How to cite this record

Max Burian, Michael Porer, Jose R.L. Mardegan, Vincent Esposito, Sergii Parchenko, Burganov Bulat, Namrata Gurung, Mahesh Ramakrishnan, Valerio Scagnoli, Hirkoi Ueda, Sonia Francoual, Federica Fabrizi, Yoshikazu Tanaka, Tadashi Togashi, Kai Rossnagel, Steven L. Johnson, Urs Staub, Structural involvement in the melting of the charge density wave in 1T-TiSe2, Materials Cloud Archive 2021.26 (2021), https://doi.org/10.24435/materialscloud:b3-e5

Description

The simultaneous condensation of electronic and structural degrees of freedom gives rise to new states of matter, including superconductivity and charge-density-wave formation. When exciting such a condensed system, it is commonly assumed that the ultrafast laser pulse disturbs primarily the electronic order, which in turn destabilizes the atomic structure. Contrary to this conception, we show here that structural destabilization of few atoms causes macroscopic melting of the charge-density wave in 1T-TiSe2. In detail, we use ultrafast pump-probe non-resonant and resonant X-ray diffraction to track the periodic lattice distortion and the electronic charge density wave in 1T-TiSe2 upon optical excitation. We observe a fluence regime in which the periodic lattice deformation is strongly suppressed but the charge density wave related Se 4p orbital order remains mostly intact. Complete melting of both structural and electronic order occurs 4-5 times faster than expected from a purely electronic charge-screening process, strongly suggesting a structurally assisted weakening of excitonic correlations. Our experimental data provides insight on the intricate coupling between structural and electronic order in stabilizing the periodic-lattice-distortion/charge-density-wave state in 1T-TiSe2. The results further show that electron-phonon-coupling can lead to different, energy dependent phase-transition pathways in condensed matter systems, opening new possibilities in the conception of non-equilibrium phenomena at the ultrafast scale.

Materials Cloud sections using this data

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Experimental_and_Model_Data.zip MD5md5:40970106380b3a0df5a89b427c45e3b9	10.9 MiB	All experimental and model data presented in the manuscript. See README.txt for further information.

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External references

Keywords

TiSe2 Charge Density Wave XFEL Transient X-Ray Diffraction MARVEL Paul Scherrer Institute SNSF