Curvature-induced polarization in carbon nanoshells

We investigate the normal polarization induced by the bending of graphite shells, which microscopically occurs because of a shift in sp² hybridization at each atomic site. Based on a rehybridization model we analytically estimate the dependence on curvature of electronic charge spill into convex region. We further performed DFT calculations and extract the radial atomic dipole by direct electronic charge density integration. A continuum analysis assigns a linear susceptibility tensor to the curvature-induced polarization and shows that this tensor is isotropic for hexagonal lattice, in agreement with microscopic model and computations. The intrinsic polarization effect can be important for nano-scale electronics.