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Comment by ndesaulniers | Hacker News Reader

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ndesaulniers

Memristors are fundamental in that they relate charge w/ flux.

Capacitors relate charge to voltage. q = Cv

Resistors relate voltage to current. v = Ri

Inductors relate current to flux. theta = Li

Before memristors, nothing related charge to flux. theta = Mq

(also, voltage is the derivative of flux over time, and current is the derivative of charge over time, which makes a nice symmetry that memristors complete)

(skimmed the article briefly, seems like they're arguing that memristors are not fundamental because hysteresis is a non-linear relationship? Can I get a TL;DR HN?)

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The article's argument is that those are not the right dimensions to look at. The way to look at fundamental electronic components is as charge and the derivatives with regard to time:

1/C * q = v (Capacitors relate charge to voltage)

R * q' = v (Resistors relate the rate of charge to voltage)

L * q" = v (Inductors relate the rate of rate of charge to voltage)

There's no room in this view for the memristor

More that it requires active and time dependent history to know the state of the device, making it not fundamental in the sense that the resistance doesn't depend on history.

It's a fair point I'd say, and they're clear that this isn't something that diminishes utility of any practical device. Just that it isn't fundamental. This seems clear if you define fundamental things as not requiring history or energy to be defined. If you don't define it that way I'm sure you can come to a different conclusion.

I only understand your comment enough to reformat it and discover the symmetry you're describing.

capacitors: charge to (flux/time)'

resistors: (charge/time)' to (flux/time)'

inductors: (charge/time)' to flux

memristors: charge to flux

It's every combination of charge or the derivative of charge over time with flux or the derivative of flux over time.

For people like me who are slow:

    cap - res      f/t
     |     |    chg   c/t
    mem - ind      flx

Squares are neat.

(Not my area of knowledge; have no real clue. Hoping someone comes along and explains further.)

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