Optomechanical control of stacking patterns of h-BN bilayer

Few-layer two-dimensional (2D) materials usually have different (meta)-stable stacking patterns, which have distinct electronic and optical properties. Inspired by optical tweezers, we show that a laser with selected frequency can modify the generalized stacking-fault energy landscape of bilayer hexagonal boron nitride (BBN), by coupling to the slip-dependent dielectric response. Consequently, BBN can be reversibly and barrier-freely switched between its stacking patterns in a controllable way. We simulate the dynamics of the stacking transition with a simplified equation of motion and demonstrate that it happens at picosecond timescale. When one layer of BBN has a nearly-free surface boundary condition, BBN can be locked in its metastable stacking modes for a long time. Such a fast, reversible and non-volatile transition makes BBN a potential media for data storage and optical phase mask.