It is known that the appearance of Klein tunneling in graphene makes it hard
to keep or localize electrons in a graphene-based quantum dot (GQD). However, a
magnetic field can be used to temporarily confine an electron that is traveling
into a GQD. The electronic states investigated here are resonances with a
finite trapping time, also referred to as quasi-bound states. By subjecting the
GDQ to a magnetic flux, we study the scattering phenomenon and the
Aharonov-Bohm effect on the lifetime of quasi-bound states existing in a GQD.
We demonstrate that the trapping time increases with the magnetic flux
sustaining the trapped states for a long time even after the flux is turned
off. Furthermore, we discover that the probability density within the GQD is
also clearly improved. We demonstrate that the trapping time of an electron
inside a GQD can be successfully extended by adjusting the magnetic flux
parameters.Comment: 10 pages, 7 figure