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Let's Get to Know Quantum Computers!

 

The age we live in is the information age. Having knowledge and using it in the most efficient way is having power. Innovative studies are carried out in various fields of science. But the discoveries that impressed me the most among these studies are in the field of Quantum Computing and Information.

While you are reading this article, your computer or phone perceives these texts as 0 and 1 and converts them into letters and numbers that make them meaningful to you. The language used by the computers we use classically is 0 and 1 digit numbers. Physically speaking, there is a current of electrons or not. It makes choice with either of these two.

Quantum computers, on the other hand, take advantage of the strange properties of quantum physics. The most basic of these is the principle of superposition and entanglement. Let's talk about these two features simply.

Superposition Concept

Thinking classically, picture a rope. When you start swinging it from both ends, your rope starts to swing in waves. If these waves overlap, two situations occur; either it creates a wave with a larger amplitude than itself or the two waves dampen each other. The main event is that the two waves that exist here overlap each other. This creates the superposition.

In quantum superposition, on the other hand, quantum objects such as electrons and photons, which have both wave and particle properties, have all possible quantum states at the same time, that is, they carry all the possibilities of information such as energy, position, velocity, momentum at once, at the same time. This seems impossible, but this has been proven by most experiments, both in Schrodinger's equation and in the double-slit experiment.

Quantum Entanglement Concept

Now let's imagine a simple experimental setup. For example, let's pass calcium atoms through a crystal. Atoms passing through the crystal will become entangled with each other. In addition, entangled particles are particles with exactly the same energy, same spin, and same momentum. Here spin forms the basic structure of quantum physics. When we flow conceptually, what we call spin is the knowledge of which direction a subatomic particle spins about a certain axis. While determining this direction, the poles of the magnet are taken as a basis. When we measure one of our entangled particles, for example, if we find the spin up, the spin of our other particle is affected at that moment and determines its spin down. However, this information was in the two particles - superposition before the measurement was made, containing both spin states at the same time.

Now that we have taken a brief look at these two concepts, we can go back to quantum computing. Quantum computers use the 0 and 1 binary systems as in classical computers. However, it does not have one of them on/off, but it has both on and off features at the same time. Because of this difference, the unit system of quantum computers is called "qubit".

How Quantum Computers Are Good?

Everything is okay so far, but why do we need quantum computers? The answer is simple. Speed, energy saving. When we are dealing with a multi-solution problem, classical computers can take a lot of time to solve it, which means a significant energy expenditure. However, quantum computers can give you the solution in the shortest way in one go. Of course, special algorithms for quantum computers, which are being developed by some companies, are currently being worked on. We do not yet have algorithms to apply to concrete problems.

I will go into detail about them in future articles. 

Stay with physics. :)

 

 

References

https://www.ibm.com/quantum


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