Andrzej M. Oleś (26.02, 13:00)
Affiliation: Jagiellonian University Title: Topological Phases by Spatially Inhomogeneous Pairing Centers Abstract:We investigate the effect of periodic and disordered distributions of pairing centers in a one-dimensional (1D) itinerant system to obtain the microscopic conditions required to achieve an end Majorana mode and the topological phase diagram. Remarkably, we observe [1] that the topological invariant can be generally expressed in terms of the physical parameters for any pairing center configuration. We identify the phase diagram with topologically nontrivial domains where Majorana modes are completely unaffected by the spatial distribution of the pairing centers [1]. These results are general and apply to several systems where inhomogeneous perturbations generate stable Majorana modes. One realization is the 1D orbital model with Majorana modes, obtained for a ruthenium oxide with charge impurities replacing a doublon by a holon orbital degree of freedom in the ferromagnetic regime [2]. We acknowledge support by Narodowe Centrum Nauki (NCN, Poland), Project No. 2016/23/B/ST3/00839. [1] W. Brzezicki, A. M. Oleś, and M. Cuoco, Phys. Rev. B 95 , 140506(R) (2017).
[2] W. Brzezicki, M. Cuoco, F. Forte, and A. M. Oleś, J. Supercond. Novel Magn. 31 , 639-645 (2018).