  In this work, we present a clear evidence, based on numerical simulations and
experiments, that the polarization compensation due to trapped charge strongly
influences the ON/ OFF ratio in Hf 0.5 Zr 0.5 O 2 (HZO)-based ferroelectric
tunnel junctions (FTJs). Furthermore, we identify and explain compensation
conditions that enable an optimal operation of FTJs. Our results provide both
key physical insights and design guidelines for the operation of FTJs as
multilevel synaptic devices.
