Ultrafast formation of topological defects in a 2D charge density wave

Abstract

Topological defects play a key role in nonequilibrium phase transitions, ranging from birth of the early universe to quantum critical behavior of ultracold atoms. In solids, transient defects are known to generate a variety of hidden orders not accessible in equilibrium, but how defects are formed at the nanometer lengthscale and femtosecond timescale remains unknown. Here, we employ an intense laser pulse to create topological defects in a 2D charge density wave, and track their morphology and dynamics with ultrafast electron diffraction. Leveraging its high temporal resolution and sensitivity in detecting weak diffuse signals, we discover a dual-stage growth of 1D domain walls within 1 ps, a process not dictated by the order parameter amplitude but instead mediated by a nonthermal population of longitudinal optical phonons. Our work provides a framework for ultrafast engineering of topological defects based on selective excitation of collective modes, opening new avenues for dynamical control of nonequilibrium phases in correlated materials.

References in corpus (7)

• Nonthermal pathways to ultrafast control in quantum materials
• A quantum phase transition from triangular to stripe charge order in NbSe${}_2$
• Optical manipulation of electronic dimensionality in a quantum material
• Light-induced dimension crossover in 1T-TiSe${}_2$ dictated by excitonic correlations
• Light-induced hexatic state in a layered quantum material
• Role of equilibrium fluctuations in light-induced order
• Dynamics of topological defects after a photo-induced melting of a charge-density wave

Cited by in corpus (14)

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• Megahertz cycling of ultrafast structural dynamics enabled by nanosecond thermal dissipation
• In-plane anisotropy of charge density wave fluctuations in 1$T$-TiSe${}_2$
• Femtosecond trimer quench cycled at megahertz rates in the unconventional charge-density wave material $1\text{T’}-{\text{TaTe}}_2$
• Frustrated phonon with charge density wave in vanadium Kagome metal
• Shot-to-shot acquisition ultrafast electron diffraction
• Fate of transient order parameter domain walls in ultrafast experiments
• Dislocation-Driven Nucleation Type Switching Across Repeated Ultrafast Magnetostructural Phase Transition
• Prospects for Direct Electron Detectors in Ultrafast Electron Diffraction and Scattering Experiments
• Mode-Dependent Phonon Relaxation in fcc Ni: Insights from Molecular Dynamics Simulations with Frozen-Trajectory Excitations
• Revisiting the charge-density-wave superlattice of 1$T$-TiSe${}_2$