# Quantum Computing

## What is Quantum Computing?

Quantum Computing at its simplest is computing using theories of quantum physics instead of traditional computing methods. To be more specific, quantum computers use processes called superposition and entanglement to be able to handle calculations much faster than traditional hardware. Google and NASA have already stated that their D-Wave 2X quantum computer is 100 million times faster than a normal computer. (1)

Traditional computers use bits, which are either 0 or 1, to perform every possible action a computer can do. However, this is not the case for quantum computers. Instead, they use something called “qubits,” which are particles that can represent 0, 1, or both simultaneously. (2) This is made possible by superposition: a unique property of particles on the quantum level. Basically, particles such as electrons or photons can exist in multiple positions at the same time when unobserved. However, once you start observing these particles, they will always end up in one defined position. Furthermore, when these particles are in a state of superposition, they can be connected to each other through an extremely strong correlation: this phenomenon is called entanglement. When particles are entangled together, interacting with one particle may change the connected particle as well. This connection between entangled particles is ever-present no matter the distance. So you could potentially have 2 entangled particles on different sides of the planet and changing the state of one particle would still affect the other particle across the world.

Now particles themselves have a magnetic charge and align themselves with the magnetic fields present, similarly to how a compass aligns itself to Earth’s magnetic field. They normally rest in the position of least resistance so we can call this position 0. Now if you were to apply a perfect amount of force to the particle, then it would stay unaligned with the magnetic field and would be considered in position 1. Applying the theory of superposition to this, we can say that these particles, or qubits, both align and don’t align with the magnetic fields at the same time when unobserved. In other words, they represent positions 0 and 1 at the same time. (3)

The unique nature of these particles is what allows us to achieve higher processing speeds in quantum computers over regular computers. The reason behind this can be explained by comparing 2 regular bits, 2 entangled qubits and the differences between them when you add additional bits and qubits. The 2 regular bits can only represent 2 numbers worth of information since each bit can only be 0 or 1. And every additional bit you add onto this will only be able to represent an additional bit of information as well. On the other hand, the 2 qubits can represent all 4 possible combinations of the 2 bits at the same time due to superposition and entanglement. So in essence, these 2 qubits are representing 4 bits of information. Every additional qubit added will increase the data representation exponentially as 3 qubits can represent 8 possible outcomes worth of information and so forth. Therefore, additional bits will increase data representation linearly while additional qubits will increase it exponentially. (3)

## D-Wave

Recently, quantum computing has become more accessible thanks to a Vancouver based company called D-Wave. They have been developing quantum computers since 1999, and have worked with some of the most influential companies such as Google and NASA to become the world’s first commercialized quantum computer supplier. Now they have branches in Japan, and California.