Nanoscale imaging of unusual photo-acoustic waves in thin flake VTe${}_2$

Abstract

Controlling acoustic phonons, the carriers of sound and heat, has been attracting great attention toward the manipulation of sonic and thermal properties in nanometric devices. In particular, the photo-acoustic effect using ultrafast optical pulses has a promising potential to optically manipulate phonons in picoseconds time regime. However, its mechanism has been so far mostly based on the commonplace thermoelastic expansion in isotropic media, limiting the spectrum of potential applications. We investigate a conceptually new mechanism of photo-acoustic effect involving the structural instability, by utilizing a transition-metal dichalcogenide VTe${}_2$ with the ribbon-type charge-density-wave (CDW). Ultrafast electron microscope imaging and diffraction measurements reveal the generation and propagation of unusual acoustic waves in the nanometric thin plate associated with the optically induced instantaneous charge-density-wave dissolution. Our results highlight the capability of photo-induced structural instability as a source of coherent acoustic waves.

arXiv comment6 pages, 5 figures

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• Ultrafast dynamics of charge density waves in 4Hb-TaSe2 probed by femtosecond electron diffraction
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Cited by in corpus (11)

• Unconventional light-induced states visualized by ultrafast electron diffraction and microscopy
• Unveiling the orbital-selective electronic band reconstruction through the structural phase transition in TaTe${}_2$
• Ultrafast all-optical manipulation of the charge-density-wave in VTe${}_2$
• Ultrafast Control of Crystal Structure in a Topological Charge-Density-Wave Material
• Megahertz cycling of ultrafast structural dynamics enabled by nanosecond thermal dissipation
• Femtosecond trimer quench cycled at megahertz rates in the unconventional charge-density wave material $1\text{T’}-{\text{TaTe}}_2$
• Unusual photoinduced crystal structure dynamics in TaTe${}_2$ with double zigzag chain superstructure
• Electronic Landscape of Group-5 Transition Metal Ditellurides $M$Te${}_2$ ($M$ = V, Nb, Ta): Multiple Crystal Phases with Local Bonds and Flat Bands
• Relative Time-of-Flight Measurement in an Ultrafast Electron Microscope
• Toward nonthermal control of excited quantum materials: framework and investigations by ultrafast electron scattering and imaging
• Atomically Resolved Acoustic Dynamics Coupled with Magnetic Order in a van der Waals Antiferromagnet