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In two recent articles in this website, we discuss Quantum Physics (QP), the remarkable scientific discovery of the 20th century that has revolutionized science as well as all aspects of our civilian and military lives.

The first article [1] discussed several mysteries of QP, notably, particle-wave duality, uncertainty principle, probabilistic interpretation of experiments, act of measurement can change what you are observing, and the superposition principle.

The second article [2] discussed what Einstein called “spooky action at a distance,” experimental verification of QP versus deterministic predictions of local hidden variable theories a la Bell’s Theorem, and quantum entanglement.

The current article discusses how Quantum Physics’ superposition principle and the concept of entanglement can lead to major breakthroughs for computer processing power and computer security.

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Our previous article “Wonders and Mysteries of Quantum Physics” discusses how Quantum Physics (QP) [1] completely revolutionized our industrial world and our daily lives since its discovery about 100 years ago. Everyday we utilize a variety of products based on Quantum Physics. [2] That article also pointed out that QP introduced many mysteries, such as particle-wave duality, the act of observation can change what we are observing, uncertainty principle, our physical laws can only give us a probabilistic, and not a deterministic, prediction of the future.

These mysteries, especially the probabilistic interpretation, or a superposition of states, led many people to question from the beginning of QP around the mid 1920s whether there is a more fundamental theory than QT that would lead to a deterministic prediction. The most famous critic was Albert Einstein, who made critical comments such as “does the moon exist even when no one is looking at it” and “God doesn’t play dice.” Many people thought that there are probably physical variables that we are not aware of. Because these variables could have different values, and if we can determine their values, then we would have a deterministic prediction.

These are known as “hidden variable” theories. Even though the usefulness of QT became more and more apparent as more and more products based on QT permeated our lives, this debate never went away, partially because no one could think of any experiment that could be done to differentiate the predictions of QT and the predictions of hidden variable theories.

That ended in 1964 when the Irish physicist James S. Bell proved a remarkable but simple theorem (now known as Bell’s Theorem) that shows that Quantum Theory and local hidden variable theories can lead to different experimental results. [3] Therefore, this is no longer an academic debate, but a debate that can be decided by experiments, which is the fundamental concept behind physics. Before we discuss Bell’s Theorem and the subsequent experimental results, we need to make a digression to discuss two precursors of Bell’s Theorem.

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