There has been a lot of buzz about quantum computing in the last few years lately. I always wondered why and how this technology is gaining more and more interest in computer science fields and physics too.
One possible scenario is how this can break cryptographic algorithms, or more like the crypto-currency field, or search and exploring algorithms. Because of the capability of how quantum computing can explore multiple scenarios at the same time using qubits, which normal or traditional computers are not able to do so using bits.
Note: This article is based on my research on quantum computing from various sources like articles, videos, Chat-gpt etc. And explaining all of them in a single article is not a viable option, and would squeeze out the amount of information to be delivered. So stay on to the upcoming articles to get complete exposure to this topic.
But what exactly makes a difference?
So first things first. What exactly are we comparing the quantum computer with? Yes, you might have already been using it to read this article. A mobile phone, A laptop, and A PC all are considered to be traditional computing machines. Which operate based on bits.

Bit is a most basic unit of computation. It consists of 2 values in its system, 0 and 1, because of which this is also called a binary system. A transistor is a device which is used to store this information in a single bit. All the devices are made of transistors, the more the count the more amount of computations we can do. A modern device like an iPhone might have a transistor count of up to 17 billion (iPhone A-17 chip). This is indeed a tremendous count, As we achieved to decrease the size of a single transistor to a size of 3nm. So Let's build an analogy here, 1 bit can store information of 1 or 0.
Now coming to quantum computing, the unit of computing is the qubit, which is a quantum representation of bits. You might have thought then this also needs to have a possible value like 0 and 1, but there is a catch here. A qubit can have both 0 and 1 at the same time( It bothered me how this is even possible).
But it works in such a way that suppose you have a coin and you flip it, based on looking into it when it lands, it either heads or tails. When the coin is in the air, it is basically in both states(heads and tails), unless it collapses into a single output(Might ring a ball for you folks who might have heard about Schrodinger's cat, which is similar to our use-case).

This is where all the difference comes into play. The ability to be in a state of 2 different values is huge. This can be understood with a simple example, if we want to store a value or represent it in binary we need 2 bits, but in the case of qubits, a 1 single bit can be both values. This is what is called a super-position, which is more related to the physics field.
A Popular Use-Case
The most common example which is given for understanding qubits is a search algorithm.
Suppose you want to search a value from a database which has like 8 counts. In classical computing, for search, we need to look into every single one of them to find the value. But in quantum computing, we can look at all possible values at the same time, because it is a superposition and can search all combinations at once. So using a quantum algorithm like Grovers(Which we are going to discuss in upcoming articles.) This can be hugely reduced.
Time Complexity for classical computing: N
Time Complexity for Quantum Computing: √N
Important Note
Everyone might think when we fully understand how a quantum computer works, they might replace the traditional computer, But it's a big No.

Because you need to understand “What does being faster than traditional computing” mean QC’s or quantum computers are not faster, but are more powerful problem solvers, because they can find all possible outcomes using their signature super-position feature. Doing day-to-day tasks like watching a YouTube video or reading this article still be much faster in traditional computing, as it's a common procedure, Whereas a QC is used to minimize the no of possible cases we need to consider.
Here comes the Wide usages of QC’s
A QC is best used to solve complex problems in cryptography or simulate things like molecules, the universe etc, finding optimizing problems such as finding the best path in a maze.
What I think or will be the implementation for QC is like this, Today we have A special core or processor specifically to process AI models, In a similar way. Having a Co-processor like QC is the future of computing. This means classical computers will continue to handle regular tasks (like word processing or web browsing), while quantum computers could handle more specialized, computation-heavy tasks in fields like cryptography, optimization, or complex simulations.

A classical computer might run a software application, while a quantum computer could be used for running certain algorithms to solve a very specific part of a problem (like breaking an encryption or simulating a chemical reaction).
All This makes sense “Theoretically”. But I still have a question and you might also have the same, but is this fundamentally different from a classical mechanism? Which is itself a huge, huge topic to be discussed. Which is going to be covered in upcoming articles.

But As of now, this article might have given you a basic idea of how a QC is different and how they can make changes in future. In the later one, we are going to learn more about topics like.
- How and when it all started, starting from the ground zero.
- Understanding at a granular level about the working of qubits. how they differ from bits.
- Take a real-time example of searching a DB using Grover's algorithm.
- The current progress on QC’s and what we have achieved till now.
- The mathematical and theoretical model behind the development of QC.
and many more, stay tuned.