A bifurcation study of the dynamics of TaO memristors

Pulse-driven memristors (resistance-switching cells) are interesting from the dynamical system point of view. When driven by periodic alternating-polarity pulses, their time-averaged dynamics may converge to fixed-point attractors [1]. Recently, we have shown that the maximum number of stable fixed points in a broad range of popular memristor models is one [2]. Here, we analyze the pulse-driven dynamics of tantalum oxide memristors using a sophisticated device model developed in Ref. [3]. Our main finding is the identification of a driving regime when two stable fixed points exist simultaneously [4]. To the best of our knowledge, such bistability is identified in a single memristor for the first time. Bifurcation curves separating pulse parameter regions corresponding to 0, 1, or 2 stable fixed points have been found analytically. Our results can be tested experimentally and are expected to be useful in future memristor circuit designs.

[1] Y. V. Pershin and V. A. Slipko, Europhys. Lett. 125,20002 (2019).
[2] V. A. Slipko and Y. V. Pershin, IEEE Trans. on Circ. and Syst. II (in press).
[3] J. P. Strachan et al., IEEE Trans. El. Dev. 60, 2194 (2013).
[4] Y. V. Pershin and V. A. Slipko, J. Phys. D: Appl. Phys. 52, 505304 (2019).