  Due to their low surface mass density, two-dimensional materials with a
strong piezoelectric response are interesting for nanoelectromechanical systems
with high force sensitivity. Unlike graphene, the two sublattices in a
monolayer of hexagonal boron nitride (hBN) are occupied by different elements,
which breaks inversion symmetry and allows for piezoelectricity. This has been
confirmed with density functional theory calculations of the piezoelectric
constant of hBN. Here, we formulate an entirely analytical derivation of the
electronic contribution to the piezoelectric response in this system based on
the concepts of strain-induced pseudomagnetic vector potential and the modern
theory of polarization that relates the polar moment to the Berry curvature.
Our findings agree with the symmetry restrictions expected for the hBN lattice
and reproduce well the magnitude of the piezoelectric effect previously
obtained ab-initio.
