Excitonic effects in solids described by time-dependent density-functional theory
|Title||Excitonic effects in solids described by time-dependent density-functional theory|
|Publication Type||Palaiseau Article|
|Author Address|| |
Reining, L (Reprint Author), Ecole Polytech, CNRS, CEA, Solides Irradies Lab, F-91128 Palaiseau, France. Ecole Polytech, CNRS, CEA, Solides Irradies Lab, F-91128 Palaiseau, France. Univ Pais Vasco, Fac Ciencias Quim, Dept Fis Mat, E-20018 San Sebastian, Basque Country, Spain. Donostia Int Phys Ctr, E-20018 San Sebastian, Basque Country, Spain. Univ Roma Tor Vergata, Ist Nazl Fis Mat, Dipartimento Fis, I-00133 Rome, Italy.
|Reining, L, Olevano, V, Rubio, A, Onida, G|
|Year of Publication||2002|
|Journal||Phys. Rev. Lett.|
Starting from the many-body Bethe-Salpeter equation we derive an exchange-correlation kernel f(xc) that reproduces excitonic effects in bulk materials within time-dependent density functional theory. The resulting f(xc) accounts for both self-energy corrections and the electron-hole interaction. It is static, non-local. and has a long-range Coulomb tail. Taking the example of bulk silicon, we show that the -alpha/q(2) divergency is crucial and can, in the case of continuum excitons, even be sufficient for reproducing the excitonic effects and yielding excellent agreement between the calculated and the experimental absorption spectrum.