Light-induced hexatic state in a layered quantum material

Abstract

The tunability of materials properties by light promises a wealth of future applications in energy conversion and information technology. Strongly correlated materials such as transition-metal dichalcogenides (TMDCs) offer optical control of electronic phases, charge ordering and interlayer correlations by photodoping. Here, we find the emergence of a transient hexatic state in a TMDC thin-film during the laser-induced transformation between two charge-density wave (CDW) phases. Introducing tilt-series ultrafast nanobeam electron diffraction, we reconstruct CDW rocking curves at high momentum resolution. An intermittent suppression of three-dimensional structural correlations promotes a loss of in-plane translational order characteristic of a hexatic intermediate. Our results demonstrate the merit of tomographic ultrafast structural probing in tracing coupled order parameters, heralding universal nanoscale access to laser-induced dimensionality control in functional heterostructures and devices.

References in corpus (5)

• Light-induced emergent phenomena in 2D materials and topological materials
• Light-induced dimension crossover in 1T-TiSe${}_2$ dictated by excitonic correlations
• Stacking, Strain, & Twist in 2D Materials Quantified by 3D Electron Diffraction
• Light-induced hexatic state in a layered quantum material
• Domain size effects on the dynamics of a charge density wave in 1T-TaS2

Cited by in corpus (13)

• Light-induced hexatic state in a layered quantum material
• Ultrafast formation of topological defects in a 2D charge density wave
• Dimensionality crossover to 2D vestigial nematicity from 3D zigzag antiferromagnetism in an XY-type honeycomb van der Waals magnet
• Relativistic ultrafast electron diffraction at high repetition rates
• Delamination-assisted ultrafast wrinkle formation in a freestanding film
• Frustrated charge density wave and quasi-long-range bond-orientational order in the magnetic kagome FeGe
• Atomic-scale tracking of topological defect motion and incommensurate charge order melting
• In-plane anisotropy of charge density wave fluctuations in 1$T$-TiSe${}_2$
• Megahertz cycling of ultrafast structural dynamics enabled by nanosecond thermal dissipation
• Dynamic phase transition into a mixed-CDW state in 1$T$-TaS${}_2$ via a thermal quench
• Femtosecond trimer quench cycled at megahertz rates in the unconventional charge-density wave material $1\text{T’}-{\text{TaTe}}_2$
• Nonthermal order by disorder
• Hexatic Phase in Covalent Two-Dimensional Silver Iodide