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arXiv · 0809.3389

Exciton-plasmon states in nanoscale materials: breakdown of the Tamm-Dancoff approximation

Myrta Grüning·Andrea Marini·Xavier Gonze
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Abstract

Within the Tamm-Dancoff approximation ab initio approaches describe excitons as packets of electron-hole pairs propagating only forward in time. However, we show that in nanoscale materials excitons and plasmons hybridize, creating exciton--plasmon states where the electron-hole pairs oscillate back and forth in time. Then, as exemplified by the trans-azobenzene molecule and carbon nanotubes, the Tamm-Dancoff approximation yields errors as large as the accuracy claimed in ab initio calculations. Instead, we propose a general and efficient approach that avoids the Tamm--Dancoff approximation, and correctly describes excitons, plasmons and exciton-plasmon states.

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Myrta Grüning, Andrea Marini, Xavier Gonze. 2008-09-19. Exciton-plasmon states in nanoscale materials: breakdown of the Tamm-Dancoff approximation. https://doi.org/10.1021/nl803717g

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