Kondo effect in a quantum dot embedded between topological superconductors*

In this work, we study the quantum transport through a single-level quantum dot in the Kondo regime, coupled to current leads and embedded between two one-dimensional topological superconductors, each hosting Majorana zero modes at their ends. The Kondo effect in the quantum dot is treated by mean-field finite-U auxiliary bosons approximation and solved by using the non-equilibrium Green's function approach. We calculate the density of states as well as the current and the differential conductance through the quantum dot to characterize the interplay between the Kondo resonance and Majorana zero modes. The results reveal that the presence of Majorana zero modes modifies the Kondo resonance exhibiting an anti-resonance structure in the density of states, leading to spin-resolved behavior of the measurable current and differential conductance. Our findings evidence the presence of non-trivial interference phenomena between the Kondo effect and Majorana zero modes. We believe the latter could be helpful to gain a deeper understanding of the behavior of the Kondo effect in connection with Majorana zero modes.