Explaining Quantum Computing (sort of)

Know all about Quantum Computing? This post is not for you. I’m going to give a beginners’ run down of quantum computing. So, let’s start simple. What do we mean by ‘quantum’. According to google the definition is ‘a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents’. Sounds a bit jargony, but simply put the study of quantum physics or quantum mechanics is describing natural processes at the smallest scales of energy such as atoms, electrons and photons.


Quantum computing uses quantum theories such as ‘superposition’ and ‘entanglement’ to improve computing power in order to answer questions that regular computers have a tough time with.

Superposition — in comparison to a regular computer that uses ‘bits’ that are defined as either 0 or 1, in quantum computing data is read from ‘qubits’ that can be in multiple states and in essence can be a combination of 0 or 1 at any one time.

Entanglement — is essentially telepathy for small particles. Think about how twins say that even when they are separated, they know how their twin is feeling. Well entanglement is the quantum theory that an extremely strong correlation exists between quantum particles that they act in unison even when separated at long distances. Therefore, when a computer ‘reads’ an entangled qubit it already knows the properties of the other without having to read it.

For a quantum computer to work and keep the qubits in these quantum states the machine needs to be really cold. If the computer is cold, there is less energy and therefore less likely that qubits can change their quantum state. The computer needs to be close to absolute 0 in temperature which his -273°C, and in order to achieve that the computer is set up in this weird chandelier looking contraption which is essentially a freezer that gets colder through its different stages until it gets to the ‘qubits’.

Quantum computers won’t replace regular computers, but they can speed up and answer questions that regular computers have difficulty with. Examples of this are computing large databases, cryptography and running simulation models of natural processes to better understand quantum physics and chemistry. Understanding molecules better can potentially revolutionise medicine!

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