Switching Polytypes and Symmetries by Discrete vdW Sliding

While the artificial design of pristine crystalline structures and the construction of dedicated periodic playgrounds for atoms and electrons in a solid have transformed our world, much is yet to be explored.

I posit that the marvels of van der Waals polytypes should go much beyond and suggest that they offer a remarkable opportunity to rapidly, efficiently, and distinctively swap between numerous different crystals, symmetries, and dispersions at will.We have recently reported several new crystals made from identical 2D layers that differ only by their stacking symmetry.

These perfectly commensurate and periodic di-atomic polytypes result in distinct electric potential steps and exclusive ladder-like polarizations owing to their various combinations of broken inversion and mirror symmetries.

Our current research focus is mono-atomic polytypes that break both symmetries and offer further fundamental insight into the purely geometric impact of the atomic positions in the unit cell.

Our preliminary experiments on graphitic polytypes detect novel internal polarizations, placing us in a great position to explore its interplay with superconductivity and orbital magnetization.The key challenge is to break the polytypes out of their commensurate meta-stable stacking and force the layers to slide at particular interfaces, only along armchair lattice orientation and for discrete inter-atomic distances.

We have recently observed that such switching is possible using external electric fields, but only in the case of polar di-atomic bilayers.

The swapping involves a thin incommensurate boundary wall encompassing a single stacking fault, which may slide rapidly in a super-lubric manner.Building on our ability to construct and distinguish adjacent polytypes, we aim to develop methods to efficiently switch between many distinctive polytypes and properties.

With robust nano-meter and nano-second swapping capabilities, we envision ground-breaking SlideTronic technologies.