In [Fig. \[sc\_fig2\]]{}(a) we can see that when the two defects are equal, both supermodes (S and A) spread equally into the two defects. However, when the defects have significant different radii ([Fig. \[sc\_fig2\]]{}(b)), the S supermode is localized in the linear defect with smallest radius ($r_{dU}=0$ in the figure) whereas the A supermode stays localized in the linear defect with larger radius ($r_{dL}=1.2\,\rm{mm}$ in the figure). In general, the transverse amplitude profiles of the supermodes can be modified by changing the difference between the radii sizes: the more different the radii of two defects are, the more localized the supermodes are in one of the defects. Thus, if one of the supermodes of the system is excited, either the S or the A, by smoothly changing the radii of the linear defects along the propagation direction it is possible to adiabatically follow the initially excited supermode of the system, which, due to the radii modification, will smoothly change its transversal amplitude profile along the propagation direction.[@johnson_adiabatic_2002] This adiabatic following, which corresponds to the so-called spatial adiabatic passage process,[@eckert_three-level_2004; @greentree_coherent_2004; @graefe_mean-field_2006; @rab_spatial_2008; @cole_spatial_2008; @ottaviani_adiabatic_2010; @benseny_atomtronics_2010; @longhi_coherent_2007; @menchon-enrich_adiabatic_2012] allows for the control of the sound propagation along linear defects in SCs. 