  We solve analytically the problem of a finite length Kitaev chain coupled to
a quantum dot (QD), which extends the standard Kitaev chain problem making it
more closely related to the quantum dot-semiconductor-superconductor (QD-SM-SC)
nanowire heterostructure that is currently under intense investigation for
possible occurrence of Majorana zero modes (MZMs). Our analytical solution
reveals the emergence of a robust Andreev bound state (ABSs) localized in the
quantum dot region as the generic lowest energy solution in the topologically
trivial phase. By contrast, in the bare Kitaev chain problem such a solution
does not exist. The robustness of the ABS in the topologically trivial phase is
due to a partial decoupling of the component Majorana bound states (MBSs) over
the length of the dot potential. As a result, the signatures of the ABS in
measurements that couple locally to the quantum dot, e.g., tunneling
measurements, are identical to the signatures of topologically-protected MZMs,
which arise only in the topological superconducting (TS) phase of the Kitaev
chain.
