The elusive memristor: properties of basic electrical circuits

TL;DR

This paper provides a comprehensive tutorial on memristors, the fourth fundamental circuit element, detailing their properties, circuit configurations, and unique behaviors such as hysteresis and tunable damping, supported by simple models.

Contribution

It offers the first detailed tutorial on memristor properties, including circuit behaviors and internal dynamics, complementing traditional circuit element pedagogy.

Findings

Memristor exhibits hysteretic current-voltage characteristics.

Ideal memristor-capacitor and memristor-inductor circuits show non-exponential charge and current decay.

MCL circuits can be tuned from overdamped to underdamped by polarity switching.

Abstract

We present a tutorial on the properties of the new ideal circuit element, a memristor. By definition, a memristor M relates the charge q and the magnetic flux $\phi$ in a circuit, and complements a resistor R, a capacitor C, and an inductor L as an ingredient of ideal electrical circuits. The properties of these three elements and their circuits are a part of the standard curricula. The existence of the memristor as the fourth ideal circuit element was predicted in 1971 based on symmetry arguments, but was clearly experimentally demonstrated just this year. We present the properties of a single memristor, memristors in series and parallel, as well as ideal memristor-capacitor (MC), memristor-inductor (ML), and memristor-capacitor-inductor (MCL) circuits. We find that the memristor has hysteretic current-voltage characteristics. We show that the ideal MC (ML) circuit undergoes non-exponential charge (current) decay with two time-scales, and that by switching the polarity of the capacitor, an ideal MCL circuit can be tuned from overdamped to underdamped. We present simple models which show that these unusual properties are closely related to the memristor's internal dynamics. This tutorial complements the pedagogy of ideal circuit elements (R,C, and L) and the properties of their circuits.