Quantum Computing 101
The basics of Quantum Computing

You’ve probably heard the term quantum many times before. Quantum physics, quantum mechanics, the quantum realm, and quantum computing. But have you ever stopped to actually ask yourself what this is? What does quantum even mean?
Well, even though quantum sounds super complex and sophisticated, it really has a simple definition: something that is very, very, very, very, incredibly small.
Quantum objects are so small, that they are measured using nanometers. Just to put that in context, 1 nanometer is equal to 0.000000001 meters.

When we work at the atomic level, the rules of regular physics don’t apply, so I’m going to have to ask you to flush out your brain and keep an open mindset going into this.
Ready? Let's do this.
Advantages of Quantum Computers
We’ll start by answering the question, why are quantum computers better than regular computers?
Well, regular computers are pretty awesome, right? They can display movies in 4k, let you play video games at 60 fps, and help you write an article about quantum computers.
Throughout the years, they have gotten incredibly advanced, gaining an incredible amount of computing power while getting smaller. Moore’s law, discovered by scientist Gordon Moore, indicates that there is an exponential relationship between the size and power of computers per year.

According to Moore’s law, the number of transistors that can be incorporated into a silicon microchip doubles every year. This indicates that the size of the transistors decreases in order to fit more in each chip.
This is why your super thin mac book air looks like this:

and not this:

Imagine having to carry the original Macintosh to school every day… I would break my back before I hit 20 years old.
There is, however, a limit to how much you can shrink classical transistors. After a certain point, the transistors get so small that they end up storing information on the atomic level. This is when things get exciting!
The fundamental laws of regular physics do not apply, and the particles start acting differently. Let’s explore how these particles act weird at the atomic level, and how we can use this behavior to build the quantum computer.
Basic Laws of Quantum Physics:
1. Superposition:
Bits are what a regular computer uses to send and receive information, and they can be either a 0 or a 1. These 0’s and 1’s can store data and do calculations, and multiple binary digits can be used to represent large numbers and perform more complex functions.
Qubits are what a quantum computer uses to transport information and do calculations. Qubits represent atoms, ions, photons or electrons, and they work together to act as computer memory and a processor.

So why are qubits special?
Qubits have the ability to be both 0 and 1 at the same time because of superposition.
The complication with superposition, however, is that the qubit can only exist in superposition until we try to measure it. When we try to measure it, it becomes either a 0 or a 1, with a 50 percent chance for each.
2. Entanglement
Entanglement occurs when two particles interact, and when entanglement occurs, the particles are treated as one.
When you learn something about one of the particles, you, by default, learn more about the other particle.
For example, let’s say that we have two particles. Before they are measured, they are in a superposition, where the probability of being a 0 or 1 is the same for both particles. Now, after we measure one of the particles, let’s say it collapses into a 1 state. This tells us that the other particle collapses into a 0 state.

How are Quantum Computers Faster than Regular Computers?
Quantum computers use both superposition and entanglement to function properly, and this combination of the two is what makes quantum computers so much faster than your ordinary computer. Quantum Computers can go through all of the possible routes to finish a task at the same time, while a normal computer has to go through each and every task individually.
The easiest way to demonstrate this is through a maze. While a normal computer would go through each and every possible route one at a time, a quantum computer can test all of the possible routes at the same time. This is made possible in quantum computers because they can exist in multiple states at the same time.
What can we use Quantum Computers for?
Quantum computers, as I mentioned before, can test all of the possible solutions at the same time. This make even the toughest of password security systems we currently use ineffective and quite useless. A quantum computer can easily get the password to your phone, computer, and even bank accounts.
So will we have no more security?
The answer is no because while quantum computer makes the current password system seem like a joke, it will introduce the idea of quantum key distributions. The quantum key distribution would keep passwords security secure because it uses the ideas of superposition and quantum entanglement to prevent any unauthorized use.
Let me elaborate. With a quantum key distribution, the qubits would lose their properties when they are measured. Meaning that if anyone tried to access your account by looking at your key, it would immediately change properties, preventing them from being able to access your account.
Key Takeaways:
- Transistors keep getting smaller and smaller until they eventually store information on the atomic level, creating the basis of quantum computers
- While regular computers use bits, which are limited to only 0 or 1, quantum computers use qubits, which can be 0 and 1 at the same time, allowing them to make the quantum computer faster than a normal computer
- Although quantum computers can seem like they will cause a lot of problems, they bring a lot of solutions with them.
Be sure to leave some claps👏 for this article and feel free to email me with any questions or comments at aneesh.ponduru@gmail.com.
