Topological Superconductors in One-Dimensional Mosaic Lattices

TL;DR

This paper investigates how mosaic modulation of on-site potentials in one-dimensional topological superconductors affects Majorana zero modes, revealing conditions for their robustness and phase transitions.

Contribution

It introduces a comprehensive analysis of topological phases in 1D mosaic lattices with various potential modulations, providing analytical phase boundary determination.

Findings

Majorana zero modes can be robust against potential strength variations.

The parity of the mosaic interval influences topological phase stability.

Analytical phase boundaries are derived using transfer matrix methods.

Abstract

We study topological superconductor in one-dimensional (1D) mosaic lattice whose on-site potentials are modulated for equally spaced sites. When the system is topologically nontrivial, Majorana zero modes appear at the two ends of the 1D lattice. By calculating energy spectra and topological invariant of the system, we find the interval of the mosaic modulation of the on-site potential, whether it is periodic, quasiperiodic, or randomly distributed, can influence the topological properties significantly. For even interval of the mosaic potential, the system will always exist in the topological superconducting phase for any finite on-site potentials. When the interval is odd, the system undergoes a topological phase transition and enters into the trivial phase as the on-site potentials become stronger than a critical value, except for some special cases in the commensurate lattices. These conclusions are proven and the phase boundaries determined analytically by exploiting the method of transfer matrix. They reveal that robust Majorana zero modes can arise in 1D mosaic lattice independent of the strength of the spatially modulated potentials.