Preprint
Topological phase transition to a hidden charge density wave liquid
07 May 2025
Abstract
Charge density waves (CDWs), electronic crystals that form within a host
solid, have long been speculated to melt into a spatially textured electronic
liquid. Though they have not been previously detected, liquid CDWs may
nonetheless be fundamental to the phase diagrams of many correlated electron
systems, including high temperature superconductors and quantum Hall states. In
one of the most promising candidate materials capable of hosting a liquid CDW,
1T-TaS2, a structural phase transition impedes its observation. Here, by
irradiating the material with a femtosecond light pulse, we circumvent the
structural phase transition to reveal how topological defect dynamics govern
the otherwise invisible CDW correlations. Upon photoexcitation, the CDW
diffraction peaks broaden azimuthally, initially revealing a hexatic state. At
higher temperatures, photoexcitation completely destroys translational and
orientational order and only a ring of diffuse scattering is observed, a key
signature of a liquid CDW. Our work provides compelling evidence for a
defect-unbinding transition to a CDW liquid and presents a protocol for
uncovering states that are hidden by other transitions in thermal equilibrium.
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Details
- Title
- Topological phase transition to a hidden charge density wave liquid
- Creators
- Joshua S. H LeeThomas M SutterGoran KarapetrovPietro MusumeciAnshul Kogar
- Resource Type
- Preprint
- Language
- English
- Academic Unit
- Physics
- Other Identifier
- 991022052806104721