  We investigate the effects of homogeneous and inhomogeneous deformations and
edge disorder on the conductance of gated graphene nanoribbons. Under
increasing homogeneous strain the conductance of such devices initially
decreases before it acquires a resonance structure, and finally becomes
completely suppressed at larger strain. Edge disorder induces mode mixing in
the contact regions, which can restore the conductance to its ballistic value.
The valley-antisymmetric pseudo-magnetic field induced by inhomogeneous
deformations leads to the formation of additional resonance states, which
either originate from the coupling into Fabry-Perot states that extend through
the system, or from the formation of states that are localized near the
contacts, where the pseudo-magnetic field is largest. In particular, the n=0
pseudo-Landau level manifests itself via two groups of conductance resonances
close to the charge neutrality point.
