Berlin 2015 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 80: Challenges in semiconductor theory
HL 80.7: Talk
Thursday, March 19, 2015, 16:30–16:45, EW 015
Piezoelectricity in planar boron nitride via a geometric phase — •Matthias Droth1 and Vitor Pereira2 — 1University of Konstanz, Germany — 2Graphene Research Centre, National University of Singapore
Due to their low surface mass density, two-dimensional materials with a strong piezoelectric response are interesting for nanoelectromechanical systems with high susceptibility. In contrast to graphene, the two sublattices in two-dimensional hexagonal boron nitride (hBN) are occupied by different types of atoms, which allows for piezoelectricity. Recently, the piezoelectric tensor of extended hBN has been calculated via density functional theory (DFT). While an analytical description of piezoelectricity does exist for hBN nanotubes, this is, to our knowledge, not the case for two-dimensional hBN. We set up a Hamiltonian that involves the strain-induced pseudomagnetic field and derive the piezoelectric tensor using the modern theory of polarization. Our findings are in exact agreement with symmetry arguments and give an analytical explanation for the piezoelectric electron-phonon coupling in planar hBN. We also provide an estimation of the coupling strength and find a piezoelectric response similar to reported DFT results.