  Recent experiments reveal that a scanning tunneling microscopy (STM) probe
tip can generate a highly localized strain field in a graphene drumhead, which
in turn leads to pseudomagnetic fields in the graphene that can spatially
confine graphene charge carriers in a way similar to a lithographically defined
quantum dot (QD). While these experimental findings are intriguing, their
further implementation in nanoelectronic devices hinges upon the knowledge of
key underpinning parameters, which still remain elusive. In this paper, we
first summarize the experimental measurements of the deformation of graphene
membranes due to interactions with the STM probe tip and a back gate electrode.
We then carry out systematic coarse grained, (CG), simulations to offer a
mechanistic interpretation of STM tip-induced straining of the graphene
drumhead. Our findings reveal the effect of (i) the position of the STM probe
tip relative to the graphene drumhead center, (ii) the sizes of both the STM
probe tip and graphene drumhead, as well as (iii) the applied back-gate
voltage, on the induced strain field and corresponding pseudomagnetic field.
These results can offer quantitative guidance for future design and
implementation of reversible and on-demand formation of graphene QDs in
nanoelectronics.
