  The edges of graphene-based systems possess unusual electronic properties,
originating from the non-trivial topological structure associated to the
pseudo-spinorial character of the electron wave-functions. These properties,
which have no analogue for electrons described by the Schrodinger equation in
conventional systems, have led to the prediction of many striking phenomena,
such as gate-tunable ferromagnetism and valley-selective transport. In most
cases, however, the predicted phenomena are not expected to survive the
influence of the strong structural and chemical disorder that unavoidably
affects the edges of real graphene devices. Here, we present a theoretical
investigation of the intrinsic low-energy states at the edges of
electrostatically gapped bilayer graphene (BLG), and find that the contribution
of edge modes to the conductance of realistic devices remains sizable even for
highly imperfect edges. This edge conductance dominates over the bulk
contribution if the electrostatically induced gap is sufficiently large, and
accounts for seemingly conflicting observations made in recent transport and
optical spectroscopy experiments. Our results illustrate the robustness of
phenomena whose origin is rooted in the topology of the electronic
band-structure, even in the absence of specific protection mechanisms.
