Magnetic brightening of carbon nanotube photoluminescence through symmetry breaking.

Shaver, Jonah; Kono, Junichiro; Portugall, Oliver; Krstić, Vojislav; Rikken, Geert L J A; Miyauchi, Yuhei; Maruyama, Shigeo; Perebeinos, Vasili · Nano Lett · 2007

basic_science · Level V

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Abstract

We report that symmetry breaking by a magnetic field can drastically increase the photoluminescence quantum yield of single-walled carbon nanotubes, by as much as a factor of 6, at low temperatures. To explain this we have developed a theoretical model based on field-dependent exciton band structure and the interplay of Coulomb interactions and the Aharonov-Bohm effect. This conclusively explains our data as the first experimental observation of dark excitons 5-10 meV below the bright excitons.

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