Research Fellows Directory
Dr Brendon Lovett
University of St Andrews
Quantum mechanics describes the behaviour of the ‘nanoworld’ of the atoms and molecules that form the building blocks of all the materials we see around us. These basic units can behave quite differently to the larger objects that they make up. To see this, imagine an experiment that measures a property of an atom - its energy say. Even if we carefully prepare the atom in a particular state, we can’t always predict the results of the energy measurement. In fact, we could get several different values, each with a certain probability.
My work is about how to use this uncertainly to our advantage in a new kind of computer. At first this may seem absurd: how can uncertainty be useful when performing a precise algorithm? The answer lies in another quantum property – interference - which means that we can combine the various probabilities in a group of atoms to make the answer appear from the vast number of possible outcomes. Since such a lot of information can be simultaneously stored in such a ‘quantum computer’, there exist algorithms that outperform conventional processors on a vast scale. For example, quantum programs could revolutionize cryptography and sensing - and they could have a huge impact on our understanding of quantum systems themselves. Building such a quantum computer is not easy: quantum states are very fragile, and their tiny extent means they are very hard to control and measure them individually. My work looks at finding ways to overcome these challenges. For example, this year I have shown how the state of a single electron can be amplified to many electrons. This has been done before, but my idea shows that the amplifying system can be very simple indeed: a completely uniform grid of electrons that might be found in many different solid state materials. The control needed is also trivial - a simple microwave source will do it. A fascinating feature of this work is that it relied on a result from the theory of numbers, a abstract branch of maths.