What Makes Quantum Computing Special?

Bits are how computers read information. They can be in two states: 0s or 1s
You can’t even tell how many bits there are!

So, what’s the difference between qubits and bits?

What is superposition?

Superposition is a term used to describe the movement of particles when it has “no real world equivalent” or in essence, these particles defy physics because they can be in two states at once (hence quantum physics). Imagine a qubit as a sphere where spin up (0) is at the north, and spin down (1) is at the south. The red line represents the qubit’s state; as you can see, its both spin up and spin down, though it is more towards the spin up state.

It is important to note that qubit states don’t have to be spin up or spin down…they can also be vertical polarization or horizontal polarization!

What is entanglement?

Entanglement signifies that the quantum states of two or more objects have reference to each other, even if those two particles are significantly far apart. For example, if you try and measure the direction of the spin for a qubit and it is spin up, a separate qubit will be spin down; thus, no matter what, their spins will be opposite. This is called the conservation of angular momentum; the choice of measurement in one location appears to be affecting the state of the particles in the other location.

Quantum entanglement is currently still unexplained!

So…what else can quantum computers do?

Quantum computers will be able to process special algorithms such as prime factoring. Prime factorization can take modern computers months or years to even process, while a quantum computer is much faster. Because of quantum superposition, an algorithm can search both the 0 and the 1 at the same instant.

With access to the prime numbers of the “secret key”, you can decrypt the messages from the public server! This is also how banks secure users’ information.

But there’s no need to worry!

Quantum computers are indeed very powerful, but it may still take a few years to be able to achieve a universal quantum computer. This is because of quantum decoherence. Qubits are extremely fragile and their ability to stay in superposition or entanglement is low because of interactions with the environment. Decoherence leads to errors in quantum information since there must be interactions between a qubit and its environment in order to read its processed data. Therefore, quantum decoherence must be solved before being able to make a universal quantum computer.

Because of decoherence, qubits will exit out of superposition and entanglement.

--

--

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store