By David Nield
Quantum mechanics – the behavior of the Universe at the smallest of scales – continues to surprise us, with scientists now have been able to successfully create a quantum object called a domain wall in laboratory settings.
For the first time, these walls can now be generated in the lab on demand, occurring when atoms stored at very cold temperatures – a scenario known as a “Bose-Einstein condensate” – group together in domains under certain conditions. The walls are the junctions between these domains.
“It’s kind of like a sand dune in the desert – it’s made up of sand, but the dune acts like an object that behaves differently from individual grains of sand,” says physicist Kai-Xuan Yao from the University of Chicago.
There has been previous research into domain walls, but they’ve never been able to be created at will in the laboratory until now, giving scientists the ability to analyze them in new ways. It turns out they act as independent quantum objects, but not necessarily in the way that scientists would expect them to.
One of the unusual observations made by the team is the way that domain walls react to electric fields, something which will need further study to untangle. For now, just being able to produce and manipulate these walls is an important step forward.
This domain wall discovery falls under the umbrella of what’s known as dynamical gauge theory – a way to test and compute the dynamics of quantum phenomena in the lab. These discoveries could explain how emergent phenomena operate in everything from materials to the early Universe.