Hello and welcome back to Curiosity.gr. In today’s article I want to tell you a little bit more about quantum computers, a new sort of computers with a very high potential.
To understand how a quantum computer works, you first have to understand how a normal computer works. The basic building unit of a computer is a bit. Bits can only store either a one or a zero which equals on and off. Bits are so small that we don’t usually work with only one bit at the time. That’s why bits get assembled into a group of eight to form the next bigger unit, a byte. A byte is already capable to store enough space for a single ASCII character like “S” for example. There are multiple other units to store more and more bits like a kilobyte (1024 bytes), a megabyte (1024 kilobytes), a gigabyte (1000 megabyte) and so on…
Inside the computer information and therefore bits, gets transferred in form of electric impulses. To do that the computer uses transistors, a semiconductor device used to amplify or switch electronic signals and electrical power. Basically, the more transistors you have in your computer, the faster the computer is able to process information and the more calculations it can do per second. Modern computers are able to do about 100.000 MIPS (million instructions per second). The problem we have got today though is, that the transistors in our computers are already that small that they only consist out of a few molecules and we can’t make them smaller anymore. That means that we can’t have more transistors without needing more space. And that’s where quantum computing can help us!
To sum up what you have to know about normal computers: They store information in the binary system in single bits which contain eighter a zero or a one. The more bits your computer can store, the more information it can store. To regulate the transfer of bits inside the computer we need transistors. A normal CPU (the “brain” of a pc) has already that many and tiny transistors that we can’t effectively increase that number anymore.
So how do quantum computers work?
While normal computers are based on the laws of classical physics, quantum computers mainly use quantum mechanics. This means for example that a bit of a quantum computer (called a qubit) is able to contain not only a one and a zero, but also both of them at the same time. This is of course very hard to imagine but actually true! In the world of quantum mechanics, a particle is in every possible state at the same time, until you take a look at it. In this moment (and just in this moment!), the universe decides for one of the possibilities. For a qubit this behavior is called superposition and enables an exponential growth of the information processing speed. Seems pretty cool right?
As you may know, you cannot buy quantum computers in normal stores yet. So how long does it still take until we all have one?
By now, quantum computers have to run at a temperature of -272°C because otherwise it is not possible to control the quantum particles. Also, as you may can imagine, they are super expansive and need a lot of energy to be run. By now only huge companies like Google or IBM and some governments invested in quantum computers and it seems to stay like that for still some time.
I hope I could help you to get a bit familiar with quantum computers and let’s hope that there will be some progress in the future so that this technology gets accessible for all of us soon!
Written by: Simon