Quantum computing for beginners
The aim of this tutorial is to explain in simple words and simulate practical quantum problems on real quantum machines. Well, I'm also a beginner in this area and I want to learn during the tutorial creation. Hopefully, after the tutorial you and me will have better understanding over quantum world and it's application in real world.
Requirements:
- basic understanding of math
- web browser
- basic knowledge or programming
In case that you don't have math or programming background you will be able to follow the course a slower pace. But with high motivation and time devoted to this area you will be able to outperform the average people.
Introduction and resources
First you may want to read this two articles for quantum computing:
Have in mind that this Quantum Computing (QC) is still developing. This is a list of useful resources that I found for myself:
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IBM Q Community - community with many people working in area of quantum computing
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IBM Q beginners guide A must read for people who want to learn quantum computing
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IBM Q Frequently asked question. A good and short information about most topics in QC for IBM Q
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IBM Q Experience Composer - a place where you can simulate or run experiments on 5 qubits machine.
Interesting videos on the topic:
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A Beginner’s Guide To Quantum Computing - short video for Quantum Computing from Dr. Talia Gershon, a materials scientist by training, came to IBM Research in 2012.
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Quantum computing explained with a deck of cards | Dario Gil, IBM Research - another short video from scientist Dario Gil, VP of Science and Solutions at IBM, provides clarity on this complex topic.
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Jarrod McClean: "Quantum Computation for the Discovery of New Materials and [...]" | Talks at Google - long video on topic: Quantum computing promises to accelerate the solution of big problems beyond our imagination
Basics for beginners
This technology is relatively new and just starting to develop in new areas other than physics. The term is born in science around 1900 and made a significant change in our understanding of the world and universe. Some of the explanations are beyond our understanding.
Qubit and superposition for beginners
Imaging rolling a dice or tossing a coin. During the roll or the toss you don't know what will be the final result. For a coin you have two states:
- head
- tail
With probability 50% for each. We can mark them with 1 - head and 0 - tail. And this is the classic representation for a bit. The working language of classical computers. For a bit you have only two states - 0 and 1.
Moving to quantum computer and respectively the qbit or quantum bit you have one more state or so called superposition. Which can be explained as having the 0 and 1 at the same time. The coin to be tail and head simultaneously.
You can imagine this as the time when the coin is in the air and you have repeating tails to heads. The same is when you roll a dice - it's getting different positions and out numbers. Of course at the end when you measure the final state you know exactly what is the result.
So the simplest imagination would be something like:
- head - 1
- tail - 0
- tossing the coin superposition
Quantum superposition of a qubit in computing is represented by quantum gates as Hadamard gate. The easiest visualization is by bloch spheres. You can read more here: Creating superposition
Entanglement
Entanglement state is a definite state . This is a way to understand how a particle would behave based on another particle. Which are not sending information or any action. There is only a relation. I'll try to explain it in this example:
Let say that you have an animal which reproduce itself by couples of male and female. So if you get and animal X and you know that parent Y is female, then you will know 100% percent certainty that the other parent is male. This is a relation defined on a higher level. You don't need to search for the second parent.
To learn more for entanglement check this: Quantum computing entanglement