← All parts of this equation

Equation 1 · Part 2 · From Origins to Frontier: A History of Post-CMOS, Neuromorphic, Photonic, and Quantum AI Compute

Symbol q

M(q)=dφdq,v(t)=M(q(t)) i(t)M(q) = \frac{d\varphi}{dq}, \qquad v(t) = M\big(q(t)\big)\, i(t)
qq

What this part means

q occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.

Its job in the formula

q occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.

The passage around this formula

…the completeness of the other five that one should exist. He named the missing element the memristor and gave it a defining relation: M(q)=dφdq,v(t)=M(q(t)) i(t)M(q) = \frac{d\varphi}{dq}, \qquad v(t) = M\big(q(t)\big)\, i(t). where M(q) , the memristance, depends on the history of charge q that has flowed through the device — which is precisely what makes a memristor’s resistance a record of its own past, and precisely why it was recognized decades later as a natural candidate for an analogue, in-memory synaptic weight [ 3 ] .

Read this part in the article →

Learn the underlying idea

A function assigns an output to each allowed input. The expression f(x) means “apply f to x”.

Open the illustrated functions: inputs become outputs guide →

See this notation across published equations →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.