Quantum Computing 101: Beginners to Intermediate - Part 1
Tags: quantum, quantumcomputing, introduction, quantummechanics
Published: 2024-01-01 20:20:07

The term quantum sounds pretty interesting, and from our childhood, we have been familiar with this term. And by hearing this term we all felt like scientists and mad geniuses. The term quantum has been used in many popular TV shows cartoons and movies. If you are a fan of MCU (Marvel Cinematic Universe) you may even find the movie called “Ant-Man and the Wasp: Quantumania”. In the movie, Quantumania is the realm where Scott Lang and his daughter Cassandra Lang got trapped or you could say she discovered the way to visit the quantum world.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/6cqvg753qcyz7l6ts01b.gif)

However, let’s get back to our main topic. The main question is what is quantum computing? Just like the movie, quantum is something or a study in physics which particularly deals with atoms or very very small particles or objects such as atoms, electrons, protons etc. behave. This has a separate term called “Quantum Physics” or we also can say “Quantum mechanics”. But obviously, we won’t find a realm of aliens or organisms living in that quantum world just like it has been shown in the movie. We could however see some bacteria, or microorganisms living there.

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Quantum Computing is however very related to quantum mechanics. In this article, we will discuss the very introduction to Quantum Computing.

## The contents are:

- _Why Learn Quantum Computing?_
- _Why does it matter?_
- _What is the difference between a Quantum Computer and a Classical Computer?_
- _Problems that classical computers face while solving certain problems._
- _How different is the Quantum world?_
- _Classical world vs Quantum World._
- _What do we focus on doing in Quantum Computing?_
- _Where are we today with Quantum Computing?_
- _Tech Giants, Universities and governments that are interested in Quantum Research and Development._
- _Conclusion._

This article will be a guide to Quantum Computing from beginner to intermediate and will kick-start your knowledge of Quantum Computing. In the future, I will try to discuss the following topics:

1. **Quantum Mechanics.**
2. **Single and Multi Quibit Circuits.**
3. **Coding in Cirq.**
4. **Quantum Teleportation.**

After I post the 2nd part of this article I will leave the link to that article here as well. At the end of the whole journey, you will have all the article links from the beginning till the end.

## But the question is why learn Quantum Computing?

In this 21st century, we have seen some emerging global problems. Global problems such as climate change, and global pandemic. Other than these global problems we are facing a lot of cyber threats as well. These sorts of problems were never seen before, or some problems were seen before but the technologies that we have built to overcome these problems are getting backdated or inefficient. As these problems are getting advanced over time, we must come up with advanced solutions to overcome these problems.

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**Why does learning Quantum Computing matter?**
Some of the most pressing issues of the 21st century may be solved with quantum technologies. Experts believe Quantum Computing can solve: food security, and cyber warfare and may even contribute to solving problems related to climate change as well.

<img width="200%" style="width:200%" src="https://media.giphy.com/media/Ztzt8zhmmpVPUiSNMX/giphy.gif">


## What is the difference between Quantum Computers and Classical Computers?
Here classical computers refer to the normal computers that we use in our day-to-day life. To understand the difference between Quantum computers and classical computers, let’s think of an example: You are a delivery man, and you have to deliver products in 50 cities in Russia. Russia as we know the biggest country in the world. So you try to figure out the shortest possible path for the journey to visit all the 50 cities, and you try to use your classical computer maybe your laptop and set up an algorithm (we will learn about this in the future), and try to figure out the shortest possible path for your journey. Believe it or not but this will take 20,000,000 years for your laptop to find the shortest path.

<img width="200%" style="width:200%" src="https://media.giphy.com/media/xUn3CsELcxapWtFUzu/giphy.gif">

**Problems that classical computers face while solving certain problems.**
From the above example, we can see that classical computers do take a huge amount of time to solve certain problems. The time taken to solve these problems can however be a bit minimized if we use some high-end computers with powerful processors, maybe by using the latest Intel Core i9–13900K you may be able to decrease a few years to find the shortest path. But “a few years” Nah, that’s still super inefficient. Ultimately we see that classical computers struggle to find the solution to a certain problem if:

1. There are large datasets involved.
2. There are a large number of possible combinations.

<img width="200%" style="width:200%" src="https://media.giphy.com/media/3oxRmvU3GAJay6F60g/giphy.gif">

**How different is the Quantum world?**
Inside the Quantum world, there are a few theories or terms we must understand and we must learn to understand the Quantum world properly.

- Superposition — Objects can be in multiple states at once.
- Tunneling — Objects can pass through physical barriers.
- Teleportation — Information can be teleported.

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## Classical world vs Quantum World

Now let’s compare our world with the Quantum world. There are a few interesting phenomena that would happen in each scenario.

Let’s think of a basketball court. And you are throwing the ball against a wall.

Classical World — you throw a classical basketball against a wall and it bounces right back to you.
Quantum world — as you have a small atom-sized basketball against a wall, it will pass (tunnels) right through the wall or sometimes it may even bounce back as well.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/vz5wfhv3ahb8hvs4luh3.gif)

Now you leave your basketball on the court to get some water as you are tired.

- _Classical World_ — You come back with the water and see the basketball is in the same spot when you left it.

- _Quantum world_ — You come back and probably it’s not in the same spot and now it may be at a different place.

As you notice inside the quantum world, the location and the position of the objects are not well defined as a characteristic in a quantum world compared to the classical world. Now you want to shoot your basketball inside the hoop.

- _Classical world:_ You shoot the basketball towards the hoop and you can see that it moves towards the hoop, will you score or not it depends on how you through it.
- _Quantum world:_ You shoot the basketball but it doesn’t move it floats in the same place, but every time you blink the ball moves a little bit closer to the hoop. It’s a quam zeno effect — in simple terms, it’s an effect where things don’t change when you are watching it or measuring it but when you look away things suddenly change.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/uavig1a68o5b1sj91wbd.gif)


At this point of this whole article, you seem to think about what sort of magical world the Quantum world is!
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To understand the Quantum world better we must understand some of the quantum mechanics as well. The 4 key properties of quantum mechanics are:

- _Superposition_ — It is the ability to be in multiple states at the same time. State could be related to location, or any other property, or this is what it is at a certain point of time at that specific time. For example, a basketball is spinning either clockwise or counterclockwise and we can say it in the classical world but in the Quantum world, it could be spinning in both directions within the probability percentage. Like, the ball is spinning at 50% of clockwise and the other 50% of counterclockwise.
- _Interference_ — States can interact with one another, adding up or cancelling out. For example, in basketball shooting it may get cancelling out or shredded in some places when entering the hoop or may add up and be the same as new.
- _Entanglement_ — Is the ability of multiple objects to be influenced by each other in seemingly impossible ways. For example, spinning a quantum basketball causes another quantum basketball to spin in the opposite direction. This happens no matter how far away they are.
- _Measurement_ — What state a quantum object is in often gives random results and changes the state of the object. For example, observing your quantum basketball in the air will make it follow one specific path even if it is in superposition.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/lyjgetvo1z497x66de4v.jpeg)

## What do we focus on doing in Quantum Computing?
The field of Quantum Computing is about trying to make computing faster and more powerful by taking advantage of these aspects of quantum mechanics and using them to our advantage. There are some challenging problems for classical computers, and they struggle to find solutions for them, such as:

- Delivery problems finding the shortest route.
- Nurse scheduling problem with too many constraints:
- Allow no more than 2 consecutive shifts
- Considering nurses who are on vacation
- Assigning nurses who work well together
- How can we search massive databases (not structured or sorted) where the data is not structured or stored to find an optimal value? (Or how do we find the needle in a haystack?)
All these problems have common things:

- Problems that involve too much searching or testing for regular computers to do quickly (massive data sets).
- Problems that require secure encryption.
- Problems that involve simulating quantum mechanical systems.
We are only talking about computer science, but if we observe, various problems exist in all kinds of industries:

- Finance
- Cybersecurity
- Biology
- Chemistry
- Aerospace
- Robotics and machine learning


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/7cjpdxisemf5ypod3ruw.jpg)

## Where are we today with Quantum Computing?
In the first quantum revolution, scientists leveraged the properties of quantum mechanics, and in the second quantum revolution is focused on controlling individual quantum systems and in turn developing powerful new technologies. It’s like if we could control the level of molecules or control the individual molecules and harness that and solve problems and use that power for computing, the world would change.


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## Tech Giants, Universities and governments that are interested in Quantum Research and Development.

The world is moving at a fast pace and tech giants are gathering more and more quantum leaders so that the world could receive this new form of technology, as it has the potential to change the world. 
_A few tech giants who are working with Quantum Computing:_

- Google quantum AI
- AWS
- Nvidia
- Microsoft
- Intel
- IBM Quantum
- Honeywell
- Toshiba

_There are a lot of startups as well who are developing their specialized approaches for many aspects of Quantum Computing:_

- Xanadu
- OQC
- Zapata
- Rigetti
- IonQ
- Strange works

_There are non-quantum companies that are integrating quantum into their business operations as well:_

- ExxonMobil
- Goldman Sachs
- Boeing
- Accenture
- JP Morgan

_There are Universities as well who are interested in Quantum Computing:_

- Princeton University.
- Google Quantum Computer Research Center.
- University of Tokyo.
- University of Science and Technology of China.
- University of Washington.
- University of Oxford.
- Duke University.
- National Institute of Standards and Technology.

Believe it or not, _Governments are also interested in Quantum Computing and they are investing millions of dollars:_

- France — 1.9B Euros (2.08B USD)
- India — 8000 Crore Rupee (1.2B USD)
- Australia — 111M ASD (75M USD)
- USA — 2.6B USD

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## Conclusion.
So, where does this quantum journey take us?

We’ve dipped our toes into the mind-bending world of Quantum Computing, explored its fascinating principles, and glimpsed its potential to revolutionize countless fields. But this is just the tip of the iceberg. From tackling global challenges like climate change and cybersecurity to unlocking medical breakthroughs and pushing the boundaries of artificial intelligence, Quantum Computing promises to reshape our world in ways we can only begin to imagine. But it’s still a theory, I just cannot come in and say Quantum Computing will give us everything that will reshape our world, but as our world is already falling apart, why not give it a chance?

Stay tuned for the next chapter, where we’ll unlock the hidden language of quantum and code our way into the future!

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## Notes for the readers.
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