Persistent orbital degeneracy in carbon nanotubes
نویسندگان
چکیده
The quantum-mechanical orbitals in carbon nanotube quantum dots are doubly degenerate over a large number of states. We argue that this experimental observation indicates that electrons are reflected without mode mixing at the nanotube-metal contacts. Two electrons occupying a pair of degenerate orbitals “shell” are found to form a triplet state starting from zero magnetic field. Finally, we observe unexpected low-energy excitations at complete filling of a four-electron shell.
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