Photoexcitation-induced Stacking Transition Assisted by Intralayer Reconstruction in Charge-Density-Wave Materials

TL;DR

This paper demonstrates that laser excitation can induce stacking order transitions in 1T-TaS2 by triggering intralayer reconstruction, revealing a new non-thermal pathway to manipulate charge-density-wave phases and electronic properties rapidly.

Contribution

It uncovers a novel laser-induced mechanism for interlayer stacking transitions driven by intralayer reconstruction, distinct from thermal phase changes, enabling ultrafast control of quantum phases.

Findings

Laser excitation induces interlayer stacking transitions.

Intralayer reconstruction facilitates phase changes.

Potential energy surfaces are significantly altered by photoexcitation.

Abstract

Laser excitation has emerged as an effective tool for probing microscopic interactions and manipulating phases of matter. Among charge density wave (CDW) materials, 1T-TaS2 has garnered significant attention due to its diverse stacking orders and photoexcited responses. However, the mechanisms driving transitions among different stacking orders and the microscopic out-of-equilibrium dynamics remain unclear. We elucidate that photoexcitation can introduce interlayer stacking order transitions facilitated by laser-induced intralayer reconstruction in 1T-TaS2. Importantly, our finding reveals a novel pathway to introduce different phases through laser excitations, apparently distinct from thermally-induced phase transitions via interlayer sliding. In particular, photoexcitation is able to considerably change potential energy surfaces and evoke collective lattice dynamics. Consequently, the laser-induced intralayer reconstruction plays a crucial role in interlayer stacking-order transition, offering a new method to create exotic stackings and quantum phases. The exploration opens up great opportunities for manipulating CDW phases and electronic properties on the femtosecond timescale.