2010/05/31 by András Pályi, Guido Burkard · 1 citation
Materials Science · Physics and Astronomy · #Carbon Nanotubes in Composites #Carbon nanotube #Carbon nanotube quantum dot #Condensed matter physics #Graphene research and applications #Hyperfine structure #Magnetic field #Materials science #Nanotechnology #Nanotube #Pauli exclusion principle #Physics #Quantum and electron transport phenomena #Quantum dot #Quantum mechanics #Quantum tunnelling #Spin (aerodynamics) #Zeeman effect #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.82.155424
published as Phys. Rev. B 82, 155424 (2010) · 15 pages, 6 figures, 2 tables; v2: published version
openalex publication_date 2010/10/14 · arxiv created 2010/11/01 · arxiv updated 2015/03/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a theoretical study of the Pauli or spin-valley blockade for double quantum dots in semiconducting carbon nanotubes. In our model, we take into account the following characteristic features of carbon nanotubes: (i) fourfold (spin and valley) degeneracy of the quantum-dot levels, (ii) the intrinsic spin-orbit interaction which is enhanced by the tube curvature, and (iii) valley mixing due to short-range disorder, i.e., substitutional atoms, adatoms, etc. We find that the spin-valley blockade can be lifted in the presence of short-range disorder, which induces two independent random (in magnitude and direction) valley-Zeeman fields in the two dots, and hence acts similarly to hyperfine interaction in conventional semiconductor quantum dots. In the case of strong spin-orbit interaction, we identify a parameter regime where the current as the function of an applied axial magnetic field shows a zero-field dip with a width controlled by the interdot tunneling amplitude, in agreement with recent experiments.