Pervasive orientational and directional locking at geometrically heterogeneous sliding interfaces.

Area of Science:

• Surface science
• Condensed matter physics
• Nanotechnology

Background:

• Controlling the motion of nanoscale objects on surfaces is essential for advanced manufacturing and manipulation.
• Previous work focused on triangular clusters on triangular substrates, limiting broader applicability.

Purpose of the Study:

• To investigate the dynamical locking of crystalline clusters on patterned substrates beyond triangular-triangular contacts.
• To generalize the understanding of orientational and directional locking for arbitrary lattice and substrate symmetries.
• To develop a formalism describing the relationship between locking orientation and direction for diverse surface interactions.

Main Methods:

• Experimental studies of crystalline cluster dynamics.
• Computational simulations of cluster-substrate interactions.
• Analysis of real- and reciprocal-space Moiré patterns.

Main Results:

• Dynamical locking occurs for crystalline clusters with arbitrary lattice structures on regular substrates.
• Locking phenomena are correlated with Moiré patterns, similar to triangular-triangular contacts.
• The relationship between locking orientation and direction is more complex for dissimilar surface symmetries.

Conclusions:

• The principles of dynamical locking extend to a wider range of crystalline cluster-substrate systems.
• A generalized formalism accurately describes the locking behavior across various symmetries.
• This work provides a fundamental framework for the diffusion and manipulation of nanoscale objects.