Exploring thickness-dependent Cu/TiOx:Cu/Ti memristor and chaotic dynamics in a real fifth-order memristive circuit

Memristors with nonlinear characteristics can replace passive devices to construct nonlinear and chaotic circuits, which gives new challenges and opportunities to traditional circuits. This paper presents a series of Cu-doped Cu/TiOx:Cu/Ti physical memristors with various TiO2 thicknesses by controlling the sputtering time, whose characteristics and mathematical models are explored based on the switching mechanism and v-i characteristics. To better characterize the effect of the physical memristor, a fifth-order memristive circuit is built based on it. With its dimensionless equations, complex coexisting behaviors of multiple kinds of attractors, including stable point attractors, limit cycles, and chaotic attractors, are numerically revealed. In addition, a hardware circuit with physical memristors is implemented, from which multiple coexisting attractors are conveniently captured, verifying the numerical simulations.