Figure 1

(Color online) Carbon nanotube quantum dot. (a) Nanotube with two top gates. The probe and signal pulses are applied perpendicular to the CNT axis. (b) Energy diagram of the lowest electron and hole states in a nanotube quantum dot versus the applied axial magnetic field $B_{\parallel }$. Owing to spin-orbit coupling, the fourfold degeneracy is split into two Kramer doubles: the lower-energy doublet involves states with parallel alignment of orbital and spin magnetic moments, whereas the higher-energy doublet has states with antiparallel alignment. With increasing $B_{\parallel }$, each state shifts according to its orbital and spin magnetic moments. (c) Equivalent energy diagram of (b) in trion picture. The states $|1⟩$ and $|2⟩$ correspond to electrons having parallel and antiparallel alignment of orbital and spin magnetic moments and the states $|3⟩$ and $|4⟩$ are formed by exciting one electron from the valence band to conductive band, respectively.Reuse & Permissions