ABS that persists over a large range of magnetic field strength. This low-energy ABS is thus purely a property of the quantum dot and not related to topological superconductivity. Provided that the spin-orbit energy $E_{so}$ is the largest energy scale within the dot region, we find that a low-energy ABS arises if the chemical potential is tuned within the Zeeman gap and if a Fabry-Perot-like resonance condition relating the spin-orbit length and the dot length ($L$) is satisfied. In particular, we find that the presence of such an ABS is insensitive to all other device properties and does not rely on smooth variations of any parameter [@Hansen:2018]. We also show that the relevant energy scale determining the Zeeman energy ($\Delta_Z$) needed to pin the ABS exponentially close to zero energy is the characteristic spacing between ABS levels $\alpha/L$ (where $\alpha/\hbar$ is the Fermi velocity in the dot region), such that the ABS remains pinned near zero energy for $\alpha/L\lesssim\Delta_Z\lesssim E_{so}$. As the low-energy ABS is a property only of the quantum dot, our analytical simplification of taking the proximitized section to have no SOI is not crucial. Therefore, the physical mechanism that we discuss giving rise to the ABS is 