Electronic transport and Klein tunneling in gapped AA-stacked bilayer graphene

We theoretically investigate the electronic transport and Klein tunneling in AA-stacked bilayer graphene (AA-BLG) encapsulated by dielectric materials. Using the four-band continuum model, we evaluate the transmission and reflection probabilities along with the respective conductances. We find that the interlayer mass-term difference induced by the dielectric materials opens a gap in the energy spectrum and couples the upper and lower Dirac cones in AA-BLG. This cone coupling induces an inter-cone transport that is asymmetric with respect to the normal incidence in the presence of the asymmetric mass-term. The energy spectrum of the gapped AA-BLG exhibits electron-hole asymmetry that is reflected in the associated intra- and inter-cone transport channels. We also find that even though Klein tunneling exists in gated and biased AA-BLG, it is precluded by the interlayer mass-term difference and instead Fabry-Pérot resonances appear.