Laser Driven Bulk-to-Layered Phase Transition

TL;DR

This paper demonstrates a novel laser-induced phase transition converting bulk crystals into layered 2D materials via nonlinear phononic mechanisms, enabling on-demand material transformations with potential applications in phase-change devices.

Contribution

It introduces a new laser-driven process for transforming bulk materials into layered van der Waals structures using polarized terahertz light and nonlinear phononic excitation.

Findings

Selective excitation of phonon modes breaks interlayer bonds.

Interlayer bonds are more susceptible to excitation than intralayer bonds.

The process enables controlled bulk-to-2D material transformation.

Abstract

Laser-induced phase transitions offer pathways of phase transitions that are inaccessible by conventional stimuli. In this study, we conduct ab initio simulations to numerically demonstrate a novel laser-induced structural transformation: converting a bulk crystal into a layered van der Waals material using intense light pulses. The transition is driven by a nonlinear phononic mechanism, where selectively exciting polar and anti-polar phonon modes with polarized terahertz light breaks targeted interlayer bonds while preserving intralayer ones. We identify that strong anisotropy in bond sensitivity where interlayer bonds are significantly more susceptible to excitation than intralayer bonds is the critical prerequisite. Our findings pave the way for on demand transformations from bulk to 2D materials, facilitate the design of advanced phase-change devices, and suggest a potential optical exfoliation method to expand the range of exfoliable 2D materials.