  The paper discusses the chiral tunnelling of charge carriers through double
barrier structure in twisted graphene bilayer. The theoretical analysis
investigates the transmission probability for various system parameters under
both symmetric and asymmetric barrier conditions. The results reveal that the
transmission probability of quasiparticles in the $K$ cone is mirror symmetric
to that of $K_{\theta}$ cone about $\varphi =0$. Furthermore, the study shows
that the transmission changes gradually from perfect transmission to perfect
reflection in the normal direction by increasing the incident energy and the
barrier height, which is different from the case of monolayer and AB-stacked
bilayer graphene. It is also found that the double barrier structure remains,
only in certain cases, perfectly transparent for normal or near-normal
incidence. The chiral nature of the quasiparticles in graphene causes the
tunneling to be highly dependent on the direction and also on the double
barrier structure. Interestingly, this characteristic provides additional
parameter that allows us to tune the electronic properties of the twisted
graphene bilayer. Additionally, we found that the transmission exhibits some
sharp resonance peaks, the number and amplitude of which depend on the system
parameters. Our results provide a better understanding of the chiral tunnelling
in twisted graphene bilayer through double barrier structures and can help in
designing efficient electronic devices.
