Thu, Mar 31, 2016, 2:00 pm to 3:30 pm
PCTS Seminar Room
Recent spin polarized scanning tunneling microscopy (SPSTM) experiments in magnetic chains  opened new routes for detecting the elusive Majorana fermions (MFs). Within the deep Shiba limit we calculate  the spatially resolved tunneling conductance of topological ferromagnetic chains [1,3] measurable by means of SPSTM. Our analysis reveals novel signatures of MFs arising from the interplay of their strongly anisotropic spin-polarization and the magnetization content of the tip. We investigate the occurrence and evolution of zero/finite bias peaks for a single or two coupled chains forming a Josephson junction, when a preexisting chiral symmetry controlling the number of MFs per chain edge is preserved or weakly broken. We also reveal alternative routes for engineering MFs without spin-orbit interaction (SOI). On one hand, we highlight that antiferromagnetic Shiba chains become topological by inducing an artificial SOI using external fields , while on the other, we pursue mechanisms for stabilizing magnetic textures and topological Shiba lattices following the self-organization principle for topological spiral chains .  S. Nadj-Perge et al., Science 346, 602 (2014).  P. Kotetes et al., Physica E 74, 614 (2015).  A. Heimes, D. Mendler, and P. Kotetes, New J. Phys. 17 023051 (2015).  A. Heimes, P. Kotetes, and G. Schön, PRB 90, 060507(R) (2014).  M. Schecter et al., arXiv:1509.07399.