Quantum physics is the next great frontier in modern science. When we look at the Universe on such a tiny scale, the picture is mind-boggling – but if we could begin to truly understand it, we could make huge technological advances and discover profound truths about the nature of reality.
Physicists at UEA are exploring fascinating quantum phenomena in the shape of whirlpools and vortices, finding them everywhere from superfluids to beams of light. Could they give us clues to the inner workings of the Universe?
Quantum physicists study the Universe at scales smaller than individual atoms, investigating the interactions between subatomic particles and the strange behaviours that result from their unique properties.
Generally, the models of ‘classical’ physics just don’t apply at the quantum level – the way tangible objects on our planet behave and move is very different to the way photons, quarks and gluons interact.
In the world of quantum mechanics, something can be in two different places; the very act of measuring a particle can affect its properties; and the rules of gravity as articulated by Newton and Einstein break down.
Theoretical physicists at UEA are looking closely at strange phenomena like ‘superfluids’, ‘optical vortices’ and ‘structured light’ to pick apart these quantum mysteries, finding surprising features that could help us explain how the strange behaviour of things as tiny as atoms can give rise to phenomena that bear strong resemblance to similar structures predicted by the classical laws of physics that govern the motion of planets.
Dr Hayder Salman, for instance, explores the properties of superfluids such as liquid helium and atomic Bose-Einstein condensates. These fascinating substances don’t experience friction, one of the properties possessed by normal viscous liquids. They can pass straight through porous media that would otherwise inhibit the flow of normal fluids, and other objects can move through them without experiencing any drag. In addition, their peculiar thermal conductivity properties means that simply shining light on them can cause them to spray like a fountain.
Dr Salman’s research has focused on the presence of miniscule vortices in superfluids, demonstrating that the classical equations governing whirlpools, tornadoes and other larger-scale rotations also map onto these quantum examples.
The correlations between swirling superfluids and other disparate phenomena can be striking. Allowing two quantum whirlpools to come into contact with each other produces an almost identical behaviour to that of two black holes colliding in space. The resultant ripples in the superfluid closely mirror the ripples in spacetime caused by two black holes (gravitational waves), leading some physicists to speculate that the vacuum permeating the Universe is actually a superfluid itself. If spacetime were a liquid, the implications for physics would be extraordinary as some scientists think it could point the way to a unification of classical mechanics, relativity and quantum mechanics.
Similarly, UEA’s Professor David Andrews from the School of Chemistry, conducts related research into one of the most important and fascinating elementary particles in the Universe: the photon. His research focuses in part on the many quantum phenomena that arise when light and matter interact, raising entirely new questions about the fundamental nature of photons.
Not only have physicists found amazing connections between whirlpools in superfluids, swirling tornadoes and roiling black holes, they’ve also recently discovered that light itself can be twisted into ‘optical vortices’.
These vortices are an exciting and fruitful object of study, as UEA’s ‘Nanophotonics and Quantum Electrodynamics Group’ has demonstrated. Not only does the study of optical vortex light have certain practical applications – from the fundamental manipulation of matter to information storage – but it also demonstrates that light is even more complex, strange and unique than we first thought.
How can something as elusive as light be twisted into a vortex? If photons are travelling in a twisted beam, are they actually travelling faster than the speed of light? What does the existence of structured light mean for wave-particle duality?
Looking at these very specific, very complicated phenomena – whether in laser beams or superfluids – brings us closer to harnessing the mysterious power of quantum mechanics and understanding the real structure of the wider Universe.