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EfficientO(N2)approach to solve the Bethe-Salpeter equation for excitonic bound states

2008/05/06 by F. Fuchs, Claudia Rödl, C. Rödl +3
Physics and Astronomy · #Advanced Chemical Physics Studies #Physics of Superconductivity and Magnetism #Semiconductor Quantum Structures and Devices #cond-mat.other

paper · pdf · doi:10.1103/physrevb.78.085103

published as Phys. Rev. B 78, 085103 (2008) · 13 pages, 12 figures, 1 table, submitted to PRB

arxiv created 2008/05/06 · openalex publication_date 2008/08/05 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

Excitonic effects in optical spectra and electron-hole pair excitations are described by solutions of the Bethe-Salpeter equation (BSE) that accounts for the Coulomb interaction of excited electron-hole pairs. Although for the computation of excitonic optical spectra in an extended frequency range efficient methods are available, the determination and analysis of individual exciton states still requires the diagonalization of the electron-hole Hamiltonian \stackrel\ifmmode \else \\fiH. We present a numerically efficient approach for the calculation of exciton states with quadratically scaling complexity, which significantly diminishes the computational costs compared to the commonly used cubically scaling direct-diagonalization schemes. The accuracy and performance of this approach is demonstrated by solving the BSE numerically for the Wannier-Mott two-band model in k space and the semiconductors MgO and InN. For the convergence with respect to the k-point sampling, a general trend is identified, which can be used to extrapolate converged results for the binding energies of the lowest bound states.

Citations