This is the final blog in this trilogy on the fascinating world of quantum physics, and yes, quantum mechanics has opened my eyes to a whole dimension of possibilities. In fact, quantum mechanics is a field of science that we use all the time. If I am being honest, it is probably something that we rely on a bit too much. So, what is the biggest use case of quantum physics in today’s day and age? Quantum is responsible for all the buzz around AI. All the top companies like Microsoft, IBM and DeepSeek are working on a branch of computing called quantum computing that can not only help progress AI but do things that even normal supercomputers would find impossible.
Quantum computing is an emerging field of computer science that harnesses the unique qualities of quantum mechanics to solve problems beyond the ability of even the most powerful classical computers. It can solve problems that a normal computer could never solve, in a matter of months. They are being used for complex tasks that we could never imagine understanding, for example, to cure cancer through simulations or representing protein folding for doctors and biologists respectively (both of which I have been told are very complex areas of science). Both of these issues were considered impossible but necessary to tackle and now with the help of these super computers, the possibility dawns closer.
Quantum computers have two main responsibilities: modelling the behaviour of physical systems as well as identifying patterns and structures in information; something humans and computers can do, but the efficiency of a quantum computer is unmatched.
The four most important principles when thinking about quantum computing is superposition, entanglement, decoherence and interference. The most important of which is superposition, which derives from the basics of quantum mechanics, the theory of Schrodinger’s cat. The principle of superposition is when two or more waves overlap, the resulting disturbance is equal to the sum of individual disturbances, but each wave does this without affecting one another which means their characteristics stay independent. Simply speaking, imagine touching the surface of a lake at two different points at the same time. The waves would spread outward until they eventually overlap. This is a superposition of water waves, but this same concept can happen with any waves. In mathematical terms it is a similar concept to how a square root can have two possible solutions, e.g. the square root of 9 can be 3 or -3.
When an electron is in superposition, its different states can be thought of as separate outcomes each with a different probability. However, the outcome is only known until it happens which is when the superposition collapses. It is science’s way to be able to exist in multiple different states at the same time.
Sunlight itself is a superposition of light. White light which we see from the sun and most man-made light sources, is a superposition of all the colours. The formation of a rainbow occurs when the superposition collapses as the light is refracted through rain droplets. There have been many experiments to prove this idea, theoretical and physical. The most famous example being the Double Slit Experiment carried out by Thomas Young.
Superposition is enormously important in quantum computing as this is how these machines store data. Rather than storing data in a bit, the smallest unit of data represented by a 0 or 1, they store data in qubits. These qubits are often created by manipulating and measuring quantum particles specifically photons and electrons as they are very small. A qubit is special as it can store data as a 0 and a 1 until it is measured. Therefore, the possibilities of storage can be 0, 1, 00, 01, 10, 11. As you can imagine, if one qubit holds so many combinations, and each combination represents a bit of data, then you can store vast amount of data with the same number of bits. When someone wishes to access this data, the multiple states collapse to form one single binary bit possibility, where it can be registered as a 0 or a 1.
Quantum mechanics is a growing part of our world and frankly where all the new innovations and discoveries lie, as well as the fascinating new world of AI. Qubits could be the secret to an eco-friendlier way of storing data without thousands of litres of water wasted cooling the data centres. If like me, you are interested in science mixed with two of the most relevant subjects, climate change and AI, then this is where our future understanding lies. Quantum mechanics is a fundamental part of all modern studies, and I believe that quantum computing in particular is a field that requires more great minds.
If you found this interesting and would like to read more on the subject I would recommend these websites;
What Is Quantum Superposition? – Caltech Science Exchange
Principle of superposition | Definition, Examples, & Facts | Britannica
What Is Superposition? (Definition, Examples) | Built In
What Is Quantum Computing? | IBM
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