Recently, the non-Hermitian skin effect has attracted significant attention. In systems exhibiting this effect, the spectrum under the periodic boundary conditions and open boundary conditions are different, i.e., the spectrum is highly sensitive to the boundary conditions. However, most of present examples of such boundary sensitivity pertain to systems related to the non-Hermiticity, and the analogous phenomena in the spectrum of a purely Hermitian system is rare. In this work, inspired by the doubled-Hamiltonian method, we present a general construction of boundary-sensitive topological phases in Hermitian multileg ladders with chiral symmetry. Then we take a $p$-wave superconducting multileg ladder as an example. We find that both the Hermitian spectrum and the topological phase of this system are sensitive to the boundary conditions perpendicular to each leg, which persists even in the presence of an impurity chain or disorders. Our work provides a possible approach for engineering spectra and topological phases via manipulating boundary conditions in some artificial Hermitian systems.

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• Topological phase transition
• 1-dimensional systems
• Non-Hermitian systems
• Tight-binding model