Magnetoelectronic excitations in single-walled carbon nanotubes

The low-frequency single-particle and collective excitations of single-walled carbon nanotubes are studied in the presence of a magnetic field. They strongly depend on the magnitude and direction of the magnetic field, transferred momentum, temperature, nanotube geometry, and Zeeman splitting. A narrow-gap nonarmchair carbon nanotube exhibits two interband magnetoplasmons, while a metallic nonarmchair carbon nanotube exhibits one interband magnetoplasmon and one interband and intraband magnetoplasmon or two interband magnetoplasmons and one intraband magnetoplasmon. The differences among these plasmons are relatively obvious when the magnetic field is oriented closer to the nanotube axis. The transferred momentum determines the plasmon frequency and the existence of plasmons. The temperature can induce an intraband magnetoplasmon or change an interband magnetoplasmon into an intraband and interband magnetoplasmon.