SU(2) and SU(4) Kondo effects in carbon nanotube quantum dots
SU(2) and SU(4) Kondo effects in carbon nanotube quantum dots
We study the SU(4) Kondo effect in carbon nanotube quantum dots, where doubly degenerate orbitals form four-electron ``shells.'' The SU(4) Kondo behavior is investigated for one, two, and three electrons in the topmost shell. While the Kondo state of two electrons is quenched by a magnetic field, in the case …