THE NUCLEUS Issue 2 Spring 2024

Unravelling the Potential of Quantum Computers A Leap into the Future of Computing

BY RUPERT HOOPER

Introduction

How do Quantum Computers work?

In the past decade, quantum computers have emerged as a revolutionary force set to re-define the limits of classical computing. Unlike traditional computers which rely on bits to process information in binary code (in 0s and 1s), quantum computers use qubits (quantum bits), leveraging the principles of quantummechanics. The main difference between a qubit and a bit is that instead of just being able to represent a 0 or a 1, a qubit can represent any proportion of 0 and 1 of both states, with a certain probability of being a 0 and a certain probability of being a 1, which is called superposition. The intellectual renaissance of development of working Quantum Computers has the potential to open up a realm of possibilities and challenges the boundaries of what was once thought possible in the realm of computing.

One concept at the very heart of Quantum Computing is the idea of the Superposition. Superposition allows qubits to exist in multiple states simultaneously, so when qubits are grouped together this can create complex, multidimensional computational spaces with unfathomable computational power. Another concept crucial to the creation of Quantum Computers is entanglement. Entanglement allows qubits to become correlated with each other, no matter how far apart they are physically. This interconnectedness can be harnessed to perform complex computations at super-fast speeds (up to 158 million times faster than a classical computer). An additional physics principle used in quantum computing is interference. Interference is created when groups of entangled qubits generate waves of probability which build on each other causing the crests of the waves to become amplified and troughs to be cancelled out. This allows quantum computers to find solutions to a problem, as a user can prepare a quantum circuit which follows an algorithm that uses interference selectively on qubits under superposition, causing solutions to be amplified and other possible outcomes to be cancelled out by interference.

One potential use of quantum computers is in drug and chemical research. Due to quantum computers’ incredible computational power, they can model complex molecules and proteins much more accurately than any current computers. Another use of quantum computers is in cryptography. As quantum computers use entanglement, this allows them to solve a lot of problems simultaneously which means in future quantum computers could be used to easily jailbreak any encryption and passwords, so they are a potential cybersecurity threat. However, quantum computers’ use of entanglement also allows them to create essentially unbreakable encryption and cryptography. Quantum computers could also be used to aid financial services due to their modelling capabilities; they could be used to help financial organizations better understand the trends and movements of the global economy. Quantum computers will likely be used to enhance Artificial intelligence and machine learning as it is far quicker at processing and analysing large unstructured data sets that are currently being used to create machine learning models. What can Quantum Computers be used for?

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