Modifying the interlayer interaction in layered materials with an intense IR laser.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Physical Chemistry

Background:

• Layered materials possess unique properties due to their structure.
• Controlling interlayer distances is crucial for applications in nanospace chemistry and catalysis.
• Existing methods for interlayer manipulation are limited.

Purpose of the Study:

• To propose and investigate a novel method for inducing transient interlayer compression in two-dimensional compound materials.
• To explore the potential of infrared laser excitation for manipulating interlayer distances.
• To demonstrate the feasibility of this approach using bilayer hexagonal boron nitride (h-BN) as a model system.

Main Methods:

• Utilizing intense infrared (IR) laser irradiation resonant with the out-of-plane optical phonon mode (A(2u) mode).
• Performing excited state molecular dynamics calculations based on time-dependent density functional theory (TD-DFT).
• Simulating the dynamic response of bilayer h-BN to laser excitation.

Main Results:

• Achieved an 11.3% transient interlayer contraction in bilayer h-BN.
• Identified interlayer dipole-dipole attraction induced by the laser-pumped A(2u) mode as the mechanism for contraction.
• The transient contraction was sustained for at least 1 picosecond (ps).

Conclusions:

• The proposed IR laser-induced transient interlayer compression is effective for layered materials.
• This technique offers a new pathway for controlling interlayer spacing in 2D materials.
• The ability to induce and control interlayer distance could enable novel chemical reactions in nanospaces.