  Any departure from graphene's flatness leads to the emergence of artificial
gauge fields that act on the motion of the Dirac fermions through an associated
pseudomagnetic field. Here, we demonstrate the tunability of strong gauge
fields in non-local experiments using a large planar graphene sheet that
conforms to the deformation of a piezoelectric layer by a surface acoustic
wave. The acoustic wave induces a longitudinal and a giant synthetic Hall
voltage in the absence of external magnetic fields. The superposition of a
synthetic Hall potential and a conventional Hall voltage can annihilate the
sample's transversal potential at large external magnetic fields. Surface
acoustic waves thus provide a promising and facile avenue for the exploit of
gauge fields in large planar graphene systems.
