  Phase change memory (PCM) devices are known to reduce in power consumption as
the bit volume and contact area of their electrodes are scaled down. Here, we
demonstrate two types of low-power PCM devices with lateral graphene ribbon
electrodes: one in which the graphene is patterned into narrow nanoribbons and
the other where the phase change material is patterned into nanoribbons. The
sharp graphene "edge" contacts enable switching with threshold voltages as low
as ~3 V, low programming currents (<1 {\mu}A SET, <10 {\mu}A RESET) and ON/OFF
ratios >100. Large-scale fabrication with graphene grown by chemical vapor
deposition also enables the study of heterogeneous integration and that of
variability for such nanomaterials and devices.
