Memristor — 4th Basic Element of Circuits

esocid writes "Researchers at HP Labs have solved a decades-old mystery by proving the existence of a fourth basic element in integrated circuits that could make it possible to develop computers that turn on and off like an electric light. The memristor — short for memory resistor — could make it possible to develop far more energy-efficient computing systems with memories that retain information even after the power is off, so there's no wait for the system to boot up after turning the computer on. It may even be possible to create systems with some of the pattern-matching abilities of the human brain. Leon Chua, a distinguished faculty member at the University of California at Berkeley, initially theorized about and named the element in an academic paper published 37 years ago. Chua argued that the memristor was the fourth fundamental circuit element, along with the resistor, capacitor and inductor, and that it had properties that could not be duplicated by any combination of the other three elements."

Comments

From the paper itself

[dfedfe]

Figure 1 in the paper explains it. The four fundamental circuit variables are current, voltage, charge, and magnetic flux. There are six ways of choosing two of these four, which correspond to differential equations relating the variables. Two of them are "given" in that charge is the time integral of current and magnetic flux the time integral of voltage: dq = idt. dphi = vdt.

As for the others, they are components. For instance, a resistor R fits in dv = Rdi. A capacitor C fits in as dq = Cdv. An inductor as dphi = Ldi, and a memristor fills in the missing dphi = Mdq.

Re:I'll admit I don't understand the classificatio

[Anonymous Coward]

I don't get what they mean by "fourth fundamental circuit element"

There are four fundamental circuit variables; current, voltage, charge, and flux.

We can define the relationships between charge and current and between flux and voltage. (charge as an integral of current, flux as an integral of voltage over time)

A resistor provides a function to relate voltage and current.
A capacitor provides a function to relate charge and voltage.
An inductor provides a function to relate flux and current.

Until now we did not know how to construct a passive device which would provide a function relating charge and flux. The only remaining combination of these fundamental variables.