  The possibility to make 10 nm scale, and low-disorder, suspended graphene
devices would open up many possibilities to study and make use of strongly
coupled quantum electronics, quantum mechanics, and optics. We present a
versatile method, based on the electromigration of gold-on-graphene bow-tie
bridges, to fabricate low-disorder suspended graphene junctions and quantum
dots with lengths ranging from 6 nm up to 55 nm. We control the length of the
junctions, and shape of their gold contacts by adjusting the power at which the
electromigration process is allowed to avalanche. Using carefully engineered
gold contacts and a nonuniform downward electrostatic force, we can
controllably tear the width of suspended graphene channels from over 100 nm
down to 27 nm. We demonstrate that this lateral confinement creates
high-quality suspended quantum dots. This fabrication method could be extended
to other two-dimensional materials.
