1205.4106 (Chi-Cheng Lee et al.)

Propagation of tightly bound excitons: a simple first-principles method
of exciton kinetics    [PDF]

Chi-Cheng Lee, Xiaoqian M. Chen, Chen-Lin Yeh, H. C. Hsueh, Peter Abbamonte, Wei Ku

A simple first-principles method is proposed to describe propagation of tightly bound excitons via its kinetic kernel. By viewing the exciton as a composite object (internally consisting of local particle and hole in Wannier orbitals), the corresponding kinetic kernel encapsulates the detailed information of the propagation and decay of the exciton, applicable for all binding energies. Case study of LiF gives three branches of exciton dispersion, which we verified via inelastic X-ray scattering. The proposed real-space picture not only offers computationally inexpensive access to the full exciton dynamics, suitable even in the presence of surfaces and impurity scattering, but also provides intuitive physical understanding necessary for the optimization of exciton propagation in semiconductors, their nanostructures, and strongly correlated oxides.

View original: http://arxiv.org/abs/1205.4106