Fig. 4: Spectrum of a CNT nanowire.
From: Zero energy states clustering in an elemental nanowire coupled to a superconductor
a Magneto-spectrum of a single shell of a CNT at small magnetic fields showing the dispersion of the four states \(\{K\uparrow,\; K\downarrow,\; K^{\prime} \uparrow,\; K^{\prime} \downarrow \}\). The green arrow indicates the zero field splitting between Kramers pairs \(\sqrt{{{{\Delta }}}_{{{{{{{{\rm{SO}}}}}}}}}^{2}+{{{\Delta }}}_{{{{{{{{\rm{KK}}}}}}}}^{\prime} }^{2}}\) and the orange arrow indicates the valley coupling \({{{\Delta }}}_{{{{{{{{\rm{KK}}}}}}}}^{\prime} }\). b Calculated addition spectrum of a CNT for two consecutive shells labeled M (blue) and N (brown), as a function of magnetic field B. The parameters, as defined in the main text, are ΔSO = −40 μeV, \({{{\Delta }}}_{{{{{{{{\rm{KK}}}}}}}}^{\prime} }=87\,\mu {{{{{{{\rm{eV}}}}}}}}\), gorb = 4.8, θ = 14° and δ = 5 meV. c Same spectrum as in a but with δ = 2 meV. The gray lines correspond to states of other shells below and above M and N. d Eight experimental energy levels dispersion of our CNT device as a function of magnetic field, extracted by following the position of Coulomb diamonds degeneracy point as measured in Fig. 2b, e. The black dashed lines are guides to the eye showing the continuity of an energy levels through the different ground states. In the legend, the symbols corresponds to the symbols of Fig. 2a.
