Few-electron physics in a nanotube quantum dot with spin-orbit coupling

Abstract

We study the few-electron eigenspectrum of a nanotube quantum dot with spin-orbit coupling. The two-electron phase diagram as a function of the length of the dot and the applied parallel magnetic field shows clear signatures of both spin-orbit coupling and electron-electron interaction. Below a certain critical length, ground state transitions are correctly predicted by a single-particle picture and are mainly independent of the length of the dot despite the presence of strong correlations. However, for longer quantum dots the critical magnetic field strongly decreases with increasing length, which is a pure interaction effect. In fact, the new ground state is spin- and valley-polarized, which implies a strong occupation of higher longitudinal modes.

6 pages, 6 figures, Minor changes with respect to first version, slightly modified value of spin-orbit coupling

References in corpus (6)

• Spin qubits in graphene quantum dots
• Coupling of Spin and Orbital Motion of Electrons in Carbon Nanotubes
• Orbital Kondo effect in carbon nanotubes
• Spin-orbit interaction and anomalous spin relaxation in carbon nanotube quantum dots
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Cited by in corpus (1)

• Coulomb versus spin-orbit interaction in few-electron carbon-nanotube quantum dots