  The coupling of charge carrier motion and pseudospin via chirality for
massless Dirac fermions in monolayer graphene has generated dramatic
consequences, such as the unusual quantum Hall effect and Klein tunneling. In
bilayer graphene, charge carriers are massive Dirac fermions with a finite
density of states at zero energy. Because of their non-relativistic nature,
massive Dirac fermions can provide an even better test bed with which to
clarify the importance of chirality in transport measurement than massless
Dirac fermions in monolayer graphene. Here, we report an electronic cloaking
effect as a manifestation of chirality by probing phase coherent transport in
chemical-vapor-deposited bilayer graphene. Conductance oscillations with
different periodicities were observed on extremely narrow bilayer graphene
heterojunctions through electrostatic gating. Using a Fourier analysis
technique, we identified the origin of each individual interference pattern.
Importantly, the electron waves on the two sides of the potential barrier can
be coupled through the evanescent waves inside the barrier, making the confined
states underneath the barrier invisible to electrons. These findings provide
direct evidence for the electronic cloaking effect and hold promise for the
realization of pseudospintronics based on bilayer graphene.
