Before we even dive into this broad topic of quantum computing, I think the best approach would be to answer the most frequently asked questions about quantum computing so that we get a base understanding of quantum computing. So let’s get started. this questions I’ve received more than 10 tens in Quora.
What is the difference between Quantum computers and other classical computers?
A quantum computer uses quantum bits or qubits which can be either 0 or 1 at the same time and this is what gives a quantum computer its superior computing power in contrast to a normal classical computer that uses bits that are basically 0s and 1s.
Here is Everything you need to know about computer logic.
There are several physical objects which can be used as qubits: a single photon, a nucleus, or even an electron. Yes, an electron asking yourself how well, we all know that electrons have magnetic fields, so they are basically like tiny bar magnets, and this property is called spin if you place them in a magnetic field they will definitely align with that field, just like a compass does with the magnetic field of the earth.
Now, this is the lowest energy state, so you could call it the zero state, or we can call it the spin down for the electron. You could also put it in one state, but that takes up some more energy.
Are Quantum computers a replacement for classical computers?
This is the most asked question about the quantum computer, but I hate to break it to you the answer is NO. Since quantum computers are not supercomputers or even universally faster. They are only faster for special types of calculations, which in that case must be complex calculations. But if you just want to use quantum computers to watch a video or browse the internet don’t expect to get any kind of improvement in terms of speed you may even be shocked to realize they are even slower at doing normal computing processes.
I think since we are looking at quantum computing it will be wise as well to know
What is quantum mechanics?
Well, there are many versions of what quantum mechanics is but I’ll just tell you my version from what I understand it’s a branch of physics just like others, which mostly deals with tiny objects which are very isolated and very cold. Computer scientists are using this knowledge in quantum to actually build new computers which actually operate on different kinds of rules than our normal computers e.g. phones.
It’s not once or twice that you ran out of phone storage, so this means that normal classical computers have a certain limit of computation power. So quantum computing comes to solve this problem by developing new machines that can adapt as the complexity of our calculations continues to rise.
What’s even more shocking is that quantum computers perform better when the problem at hand is more complex. When this technology is applied at the right places, the end product is just unimaginable. Scientists are still working on perfecting it and as we are talking right now they are real life-applications of quantum mechanics, maybe you are using them without even realizing it. A good and obvious example is cryptography.
Read about all the use cases and applications of quantum mechanics.
By now you have a little clue about what quantum mechanics is, so dive a little bit into the quantum computing world let’s start by learning superposition.
What is superposition?
The ability of a quantum system to be in multiple states at the same time until it is measured. A good real-life example is a spinning coin when the coin is rotating we can’t actually state if the side facing us is either heads or tails that’s obvious because it’s spinning now which leads us to entanglement from the word itself it means something joined or intertwined. The same applies to quantum computing.
If two entangled pennies are spun they are obviously going to rotate in the same direction and if they were to be stopped they will stop on one side either tails or heads. So by using a dilution refrigerator which is actually a refrigerator that is made to be so cold to cool quantum chips, the coldness is effective for creating superposition and then entangling quantum chips the more spins the more memory and more memory means faster computing processes.
This leads us to the third property of quantum mechanics, which is interference.
What is interference?
Interference is the net effect of the combination of two or more wave trains moving on intersecting or coincident paths. This interference can be used to control quantum states and actually amplify the kind of signals that are towards the right answer and cancel the ones that are leading to the wrong answer.
How are quantum computers made?
The first step is that you need to have a physical object and by physical I mean qubits which can actually handle superposition entanglement and interference. Also, you have to remember Not many objects in our real world can be able to be entangled therefore to achieve this quantum state we need things like ions, atoms, and in this case, superconducting qubits which are made from superconducting material.
Overall this process to make quantum computers is actually very expensive and needs to be done by experts in this field, but research is still ongoing on how these computers are going to be accessible to anyone in the world even at your office or even in your basement. Actually, a quantum model which is run in the cloud is accessible so that people can go try it for themselves and unlock the supercomputing power of this machine.