We introduce a frustration-free, one-dimensional model of spinless fermions with hopping, $p$-wave superconducting pairing and alternating chemical potentials. The model possesses two exactly degenerate ground states even for finite system sizes. We present analytical results for the strong Majorana zero modes, the phase diagram, and the topological order. Furthermore, we generalize our results to include interactions.

• Received 22 August 2018
• Revised 18 September 2018

DOI:https://doi.org/10.1103/PhysRevB.98.155119