# Memristor equations: incomplete physics and undefined passivity/activity

## TL;DR

This paper critically examines the fundamental physics of memristor equations, revealing they are incomplete regarding passivity and can lead to unphysical results, challenging the claim of memristors as a missing circuit element.

## Contribution

It demonstrates that current memristor equations are physically incomplete and violate thermodynamic principles, suggesting the need for more comprehensive models including fluctuation dissipation theory.

## Key findings

- Memristor equations can violate the Second Law of thermodynamics.
- Current models are incomplete regarding passivity and activity.
- Memristor physics requires incorporation of thermodynamics and fluctuation dissipation theory.

## Abstract

In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, "The missing circuit element". The memristor equations were originally supposed to represent a passive circuit element because, with active circuitry, arbitrary elements can be realized without limitations. Therefore, if the memristor equations do not guarantee that the circuit element can be realized by a passive system, the fundamental physics claim about the memristor as "missing circuit element" loses all its weight. The question of passivity/activity belongs to physics thus we incorporate thermodynamics into the study of this problem. We show that the memristor equations are physically incomplete regarding the problem of passivity/activity. As a consequence, the claim that the present memristor functions describe a passive device lead to unphysical results, such as violating the Second Law of thermodynamics, in infinitely large number of cases. The seminal memristor equations cannot introduce a new physical circuit element without making the model more physical such as providing the Fluctuation Dissipation Theory of memristors.

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Source: https://tomesphere.com/paper/1703.09064