Magnetic brightening of carbon nanotube photoluminescence through symmetry breaking.
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.
Shaver
Jonah
J
Department of Electrical & Computer Engineering and Carbon Nanotechnology Laboratory, Rice University, Houston, Texas 77005, USA.
Kono
Junichiro
J
Portugall
Oliver
O
Krstić
Vojislav
V
Rikken
Geert L J A
GL
Miyauchi
Yuhei
Y
Maruyama
Shigeo
S
Perebeinos
Vasili
V
D049449:Luminescence; D008280:Magnetics; D037742:Nanotubes, Carbon / Q000737:chemistry*
D037742:Nanotubes, Carbon