In this seminar I will discuss the Majorana correlations in quantum impurities coupled to a topological superconducting wire. By means of the density matrix renormalization group (DMRG) approach, the Majorana correlation functions have been calculated (for the ground state of the system) for different coupling positions of the impurities along the wire and length of the wire. We have observed that the correlation decreases exponentially with the distance between the impurities and the ends of the wire. Moreover, different electron-electron interactions on the wire (and on the impurities) were also analyzed, and the results showed a stronger effect as the electron occupation in the wire is increased. In addition, while changing the occupation of the impurities by tuning their energy levels, we have observed that for specific values of ϵ (impurities' chemical potential), the absolute value of correlation is highly peaked when the chemical potential lies within the window of the topological regime. These peaks are associated to Coulomb blockade phenomena in the impurities, revealing unambiguously its effect on the Majorana bound states in the topological phase of the system.

Reference: G. S. Diniz and E. Vernek: arXiv:2208.09524.