Memcapacitance Induced by Polarization Modulation in Dielectrically Anisotropic Ferroelectrics

Ferroelectrics with electrically switchable polarization has been used as gate material in ferroelectric field effect transistor (FET) for nonvolatile random access memory. To solve the interface problem between ferroelectric oxide and silicon, another design of one FET connected with one ferroelectric capacitor (1T-1C) has been investigated. However, the destructive readout and the complex architecture of 1T-1C ferroelectric memory limit its reading speed and recording density3. Here, we explored the possibility of single ferroelectric capacitor (1C) memory cell, utilizing electric field modulated polarization rotation in ferroelectrics with large dielectric anisotropy that depends on polarization direction. Capacitance tunability of 300% has been achieved in Pb(Mg, Nb)O₃-PbTiO₃ (PMN-PT) capacitor (C_s). A reference capacitor (C_ref) with series connection with the memory capacitor was used for information readout. The voltage value on C_ref can be changed by > 2 times in the prototype 36-cell (PMN-PT) memory. These experiments illustrate the working principle of the 1 C dielectric memory which promises simpler architecture, higher density and faster operation speed. Moreover, the memcapacitive behavior may find application in the study of neuromorphic circuits for simulating of biological processes.