Charge-density-wave quantum critical point under pressure in 2H-TaSe2
Abstract The presence of a quantum-critical point (QCP) at which a nearby ordered phase is suppressed to zero temperature is often invoked to explain emergent quantum phases, e.g. superconductivity. Yet, identifying a QCP and establishing its correlation with superconductivity remains challenging. Materials featuring charge-density-wave (CDW) order and superconductivity offer a clear scenario as both states can be associated with electron-phonon coupling. Here, we uncover a CDW-QCP and demonstrate its interrelation with superconductivity in the prototypical transition-metal dichalcogenide 2 H -TaSe 2 . We determine the evolution of the CDW state up to and beyond its suppression at the critical pressure p c = 19.9(1) GPa by means of X-ray diffraction and inelastic X-ray scattering measurements providing a full crystallographic refinement of the commensurate CDW superstructure. The pressure-induced CDW-QCP in close vicinity to the maximum superconducting transition temperature. Ab-initio lattice dynamical calculations corroborate that 2 H -TaSe 2 features order-parameter fluctuation enhanced superconductivity and can serve as a paradigm to investigate superconductivity near a CDW-QCP.
Authors
- F. Weber (ORCID: https://orcid.org/0000-0002-4256-1354)
- R. Heid (ORCID: https://orcid.org/0000-0002-2144-1417)
- Kai Roßnagel (ORCID: https://orcid.org/0000-0001-5107-0090)
- Stephan Rosenkranz (ORCID: https://orcid.org/0000-0002-5659-0383)
- Michael Merz (ORCID: https://orcid.org/0000-0002-7346-7176)
- Adrian Merritt
- Tom Lacmann (ORCID: https://orcid.org/0000-0001-7795-306X)
- Y. V. Tymoshenko
- Florian Diekmann (ORCID: https://orcid.org/0000-0002-8877-710X)
- Amir A. Haghighirad (ORCID: https://orcid.org/0000-0003-4723-4966)
- GARBARINO Gaston Leonel (ORCID: https://orcid.org/0000-0003-4780-9520)
- Alexeï Bosak (ORCID: https://orcid.org/0000-0001-8199-2301)
- Xingchen Shen (ORCID: https://orcid.org/0000-0003-1293-1067)
- L. Paolasini
- Ayman Said
- Alsu Ivashko
Institutions
- Karlsruhe Institute of Technology (DE)
- Argonne National Laboratory (US)
- Centre National de la Recherche Scientifique (FR)
- Deutsches Elektronen-Synchrotron DESY (DE)
- European Synchrotron Radiation Facility (FR)
- Hochschule für Angewandte Wissenschaften Kiel (DE)
- Christian-Albrechts-Universität zu Kiel (DE)
- Laboratoire de Cristallographie et Sciences des Matériaux (FR)
Publication Details
- Journal
- Communications Physics
- Published
- 2025-08-26
- DOI
- https://doi.org/10.1038/s42005-025-02254-3
- Primary Topic
- Organic and Molecular Conductors Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Deutsche Forschungsgemeinschaft