Quantum physThe dark and light cat images arise respectively due to destructive and constructive quantum interference, and are obtained by detecting entangled photons that never interacted with the object itself. Image credit: Gabriela Barreto Lemos and Victoria Borish. Design: Patricia Enigl. Copyright: Austrian Academy of Sciencesics is the study of the nature and behaviour of particles at a subatomic level. As one of the strangest yet most successful theories of our times, it states that particles are able to exist in two places or more at once (superposition principle), travel through impenetrable barriers (tunnel effect) and even behave like waves or particles depending on the way you measure them – confusing stuff. Even weirder features show up when considering groups of quantum particles, whose individual properties can be strongly intertwined to one another irrespective of their distance (entanglement). All of these phenomena, although experimentally confirmed, remain debated and mind-blowing with respect to our common experience. Nevertheless, it is spooky features like these that have nowadays important ramifications in the real world for the technologies of the future.

Look, for example, at computing. The use of computers is an everyday fact of life for many of us. They can be found in everything, from cars to toasters, and our digital society is only expected to become increasingly reliant on them. The Semiconductor Research Corporation have estimated that by 2040, we will not have the capability to power all worlds machines as there will not be enough electrical power to do so. It is therefore essential that we develop faster, smaller, and more energy-efficient computers. The answer to this problem may lay indeed in the strange world of quantum physics.

Traditional computers are able to store information as either the number zero (0) or one (1), this is known as binary information. The computer functions by creating different sequences of 0’s and 1’s to carry out different tasks. Unlike conventional computer, quantum computers are able to store information as a 1 and a 0 at the same time, thanks to the superposition principle. Therefore the information within a quantum computer is able to exist in multiple states at once.

Quantum computing essentially takes advantage of the ability of subatomic particles to exist in a superposition of more than one state at any time. Let’s imagine asking a traditional computer to do a calculation where you wanted to try lots of different numbers to see which one was correct. The computer would have to do one calculation at a time, in order to try each different number. In comparison, a quantum computer would be able to carry out the same task much faster as it can try out multiple numbers at the same time, all whilst using a lot less energy. The future of quantum technology will be able to tackle a huge range of modern day issues, and has the potential to solve some of the world’s most challenging problems; from extremely precise sensing to machine learning.

The use of quantum computing is looking particularly promising within the pharmaceutical field. Each year pharmaceutical companies spend billions researching new drugs and making them available to the public. However, quantum computing has the potential to drastically change and improve this process. By running suitably designed chemistry simulations, with the ability to analyse millions of drug combinations that would not be possible otherwise using traditional computers, quantum computers will allow for much faster discovery of new drugs that have the ability to cure a range of diseases.

As quantum computers and related technologies relying on quantum effects become more readily available, they will be sure to revolutionise the 21st Century. Such a process, however, inextricably requires a deeper understanding of the fundamental signatures of quantum physics and how they can be correctly interpreted, and exploited, to unveil the secrets of Nature. Join us at the Scientific Discussion meeting, Foundations of quantum mechanics and their impact on contemporary society taking place on 11 – 12 December, to investigate the profound meaning of quantum physics, and how is changing the world we live in.