  Engineering devices with a large electrical response to magnetic field is of
fundamental importance for a range of applications such as magnetic field
sensing and magnetic read-heads. We show that a colossal non-saturating linear
magnetoresistance (NLMR) arises in two-dimensional electron systems hosted in a
GaAs/AlGaAs heterostructure in the strongly insulating regime. When operated at
high source-drain bias, the magnetoresistance of our devices increases almost
linearly with magnetic field reaching nearly 10,000% at 8 Tesla, thus
surpassing many known non-magnetic materials that exhibit giant NLMR. The
temperature dependence and mobility analysis indicate that the NLMR has a
purely classical origin, driven by nanoscale inhomogeneities. A large NLMR
combined with small device dimensions makes these systems a new and attractive
candidate for on-chip magnetic field sensing.
