Mapping the nonequilibrium order parameter of a quasi-two dimensional charge density wave system
Abstract The driving force of a charge density wave (CDW) transition in quasi-two dimensional systems is still debated, while being crucial in understanding electronic correlation in such materials. Here we use femtosecond time- and angle-resolved photoemission spectroscopy combined with computational methods to investigate the coherent lattice dynamics of a prototypical CDW system. The photo-induced temporal evolution of the periodic lattice distortion associated with the amplitude mode reveals the dynamics of the free energy functional governing the order parameter. Our approach establishes that optically-induced screening rather than CDW melting at the electronic level leads to a transiently modified potential which explains the anharmonic behaviour of the amplitude mode and discloses the structural origin of the symmetry-breaking phase transition.
Authors
- Charles J. Sayers (ORCID: https://orcid.org/0000-0002-3777-5155)
- Emma Springate (ORCID: https://orcid.org/0000-0002-9121-3698)
- Adam S. Wyatt (ORCID: https://orcid.org/0000-0001-8625-6709)
- Enrico Da Como (ORCID: https://orcid.org/0000-0002-5878-371X)
- Gourab Chatterjee (ORCID: https://orcid.org/0000-0002-0972-6452)
- Giulio Cerullo (ORCID: https://orcid.org/0000-0002-9534-2702)
- E. Carpene (ORCID: https://orcid.org/0000-0003-3867-8178)
- Richard T. Chapman (ORCID: https://orcid.org/0000-0002-4622-8305)
- Charlotte E. Sanders (ORCID: https://orcid.org/0000-0003-0776-4671)
- D. Wolverson (ORCID: https://orcid.org/0000-0002-5578-6018)
- Yu Zhang (ORCID: https://orcid.org/0000-0001-6184-4870)
Institutions
- SLAC National Accelerator Laboratory (US)
- Research Complex at Harwell (GB)
- Menlo School (US)
- University of Bath (GB)
- Politecnico di Milano (IT)
Publication Details
- Journal
- Communications Physics
- Published
- 2024-11-28
- DOI
- https://doi.org/10.1038/s42005-024-01879-0
- Citations
- 2
- Primary Topic
- Organic and Molecular Conductors Research
- Type
- article
- Field-Weighted Citation Impact
- 0.24
Funders
- Ministero dell’Istruzione, dell’Università e della Ricerca
- Horizon 2020 Framework Programme