  Disorder-induced magnetoresistance (MR) effect is quadratic at low
perpendicular magnetic fields and linear at high fields. This effect is
technologically appealing, especially in the two-dimensional (2D) materials
such as graphene, since it offers potential applications in magnetic sensors
with nanoscale spatial resolution. However, it is a great challenge to realize
a graphene magnetic sensor based on this effect because of the difficulty in
controlling the spatial distribution of disorder and enhancing the MR
sensitivity in the single-layer regime. Here, we report a room-temperature
colossal MR of up to 5,000% at 9 T in terraced single-layer graphene. By
laminating single-layer graphene on a terraced substrate, such as TiO2
terminated SrTiO3, we demonstrate a universal one order of magnitude
enhancement in the MR compared to conventional single-layer graphene devices.
Strikingly, a colossal MR of >1,000% was also achieved in the terraced graphene
even at a high carrier density of ~1012 cm-2. Systematic studies of the MR of
single-layer graphene on various oxide- and non-oxide-based terraced surfaces
demonstrate that the terraced structure is the dominant factor driving the MR
enhancement. Our results open a new route for tailoring the physical property
of 2D materials by engineering the strain through a terraced substrate.
