Moore’s Law and its Current Challenge

By Jay Jagannath

When one dwells in Computer Science, Computer Engineering and related disciplines, the phrase ‘Moore’s Law’ comes up a lot. So, what is Moore’s Law?

Moore’s law refers to an observation made by Intel co-founder Gordon Moore in 1965. He noticed that the number of transistors per square inch in computer processors had doubled every year since their initial invention in 1947.(The transistor is like an electronic switch. It can turn a current on and off and hence create different kind of electronic signals.)

Moore’s law predicts that this trend will continue into the foreseeable future. Although the pace has slowed, the number of transistors per square inch has since doubled approximately every 18 months. This is used as the current definition of Moore’s law.

It must be noted that Moore’s law is not a natural law or a definite observation, but rather a generalisation of a trend in computer technology.

However, in 2015 Gordon Moore foresaw that the rate of progress would reach saturation: “I see Moore’s law dying here in the next decade or so.”

This raises an important question. To the layman, it seems logical that more and more transistors can be fit into the same space by continuously reducing their size. However, can this process continue until the transistors are of an infinitely small size?

The answer is no and the reason for this lies in the principles of quantum mechanics.

Quantum mechanics, in general terms, is the behaviour of matter and energy on infinitesimally microscopic scales, at the level of an atom or even an electron. At these microscopic levels, the regular laws of physics do not apply and instead give rise to comparatively chaotic and unpredictable behaviour, known as quantum phenomena.

One of the quantum phenomena preventing the small-sizing of transistors is known as quantum tunnelling. In the quantum world, matter is so small that its exact position and velocity is indeterminable, hence existing in a probability zone (known as a probability wave-function), wherein the particle can be said to exist. As the probability zone can pass traditional barriers (of a small enough size) that may otherwise stop the particle from moving past it, the particle can actually pass through small enough barriers that should otherwise stop the particle.

Applying this concept in the case of transistors, we see that when the transistors are small enough in size, infinitesimally small moving electrons (that create current) can pass through the small transistors, effectively rendering the transistor useless.

Such problems call for new innovation in the field of computer science and one of them is the still fledgeling quantum computer which is still too primitive for commercial application.

Only time can tell whether the progress in computer technology stagnates or accelerates.