A (Very) Brief Primer on Quantum Mechanics and Quantum Computing
Over the coming weeks, we will be publishing a two-part series detailing our recent Quantum Computing research.
Author: Tyler Jones
Entering the 20th century, a budding physicist could be forgiven for feeling that the underlying laws of the universe were all but discovered. To the average 19th century citizen, the rules of classical mechanics appeared to dictate the behaviour of all known objects, from the quintessential apple falling on Isaac Newton’s head, to the orbiting of the planets around the Sun. Behaviour on any macroscopic scale appeared to steadfastly obey these laws, whilst future models would surely describe a more complex combination of these most basic of laws.
You can imagine then, the extent to which the field of physics was transformed when the pioneers of quantum mechanics (Schrödinger, Heisenberg and Einstein among them) stumbled upon the fact that these laws were completely inapplicable at the microscopic level. Indeed, the behaviour observed and explained by classical mechanics was simply a large-scale generalisation of this incredibly unintuitive small-scale behaviour, which was based on principles such as the impossibility of knowing the speed and position of an object simultaneously, and wave-like interference between objects which had long since been established to be particles.
Researchers set to work in constructing a model which incorporated this new behaviour into our understanding of the universe, and today we are fortunate enough to live in a time where this scaffolding has been erected. The current challenge lies in exploiting these new-found laws to improve the technology we’ve already built, or to shift the paradigm altogether. This challenge motivates the search for a way to reliably enhance the process of computation with quantum mechanics.
Classically, the two-level computing bit takes the value of either zero or one. As you might have guessed, quantum mechanics disregards this notion entirely in favour of its own laws. It is thought that the additional degree of freedom afforded by the quantum mechanical interpretation of a bit, in principle, should lend itself to faster computation for a certain class of difficult problems that cannot be attained by a classical computer.
In reality, this faster computation is yet to be achieved, largely due to the difficulty in wrangling these quantum bits; these struggles are borne from the fact that quantum bits only behave well when completely isolated from their external environments. Unfortunately, some level of control over these bits is needed in order to manipulate them for computation. Intuitively, control and isolation are very difficult tasks to perform in conjunction.
This, in essence, is the problem we wish to contribute to solving; finding a way to manipulate quantum bits in very specific ways to perform certain computations, whilst not disturbing them in such a way that the computation is rendered useless.
Over the coming weeks, we will be publishing a two-part series detailing our recent Quantum Computing research. Part I of this series will delve into the use of quantum mechanics in order to facilitate efficient computation. Then, as we seek to tackle the paradox of simultaneous control and isolation of quantum bits, Part II will discuss how we intend to hand the problem over to machines through reinforcement learning.
