Classical mechanics technique for quantum linear response

Abstract

It is shown that the lowest excitation energies of a quantum many-fermion system in the random phase approximation (RPA) can be obtained by minimizing an effective classical energy functional. The minimum can be found very efficiently using generalized Lanczos technique. Application of the new technique to molecular spectra allows to compute excited states at the expense comparable to the ground-state calculations. As an example, the first-principle RPA excitation spectrum of C60 molecule is computed taking into account all 240 valence electrons in the full valence space of the molecule. The results match linear absorption experiment within percents.

4 Revtex pages; 2 PS figures embedded

References in corpus (1)

• A Lanczos algorithm for linear response

Cited by in corpus (5)

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• Linear-scaling time-dependent density-functional theory in the linear response formalism
• Linear-scaling time-dependent density-functional theory (TDDFT) beyond the Tamm-Dancoff approximation: obtaining efficiency and accuracy with in situ optimised local orbitals
• Reduction of the RPA eigenvalue problem and a generalized Cholesky decomposition for real-symmetric matrices
• Fractional charge revealed in computer simulations of resonant tunneling in the fractional quantum Hall regime