Memistor

A memistor is a theoretical two-terminal electronic component conceived as a dual to the memristor. While a memristor relates electric charge to magnetic flux linkage, a memistor is hypothesized to relate electric current to the integral of voltage across the component over time (i.e., charge).

The defining characteristic of a memistor is that its resistance depends on the history of the current that has passed through it, specifically on the integral of the voltage over time. This contrasts with resistors, capacitors, and inductors, which have fixed resistance, capacitance, and inductance values (ideally) independent of past signals. It also differs from memristors, whose resistance depends on the history of charge flow.

The concept of the memistor was introduced as a missing fourth fundamental circuit element alongside the resistor, capacitor, and inductor by Leon Chua in his 1971 paper. It was part of a theoretical framework to demonstrate the potential for circuit elements with history-dependent properties. Unlike the memristor, whose physical realization was claimed in 2008 with a solid-state device, the memistor remains theoretical and no physical implementation has been widely accepted.

Key characteristics of a theoretical memistor include:

• Non-volatility: Its resistance state persists when power is removed.
• State-dependent resistance: The resistance value changes depending on the integral of the voltage across the device.
• Two-terminal device: Like other basic circuit elements, it has only two terminals for connection.

The potential applications for memistors, if they could be practically realized, are similar to those proposed for memristors, including:

• Non-volatile memory: Storing information based on the history of the applied voltage.
• Neural networks: Emulating the behavior of synapses in the brain.
• Analog computation: Performing complex calculations using analog circuits.