Physicists at the University of Bonn, Germany, have succeeded in putting a superconducting gas into an exotic state. The experiment allows new insights into the properties of the Higgs particle.
This experiment that sees into the properties of the Higgs particle also allows insights into the fundamental characteristics of superconductors.
Scientists at the University of Bonn used a gas made of lithium atoms for their experiments, which they cooled down significantly. At a certain temperature, the state of the gas changes abruptly: it becomes a superconductor that conducts a current without any resistance.
Physicists also speak of a phase transition. A similar sudden change occurs with water when it freezes.
The lithium gas changes to a more orderly state at its phase transition. This includes the formation of so-called ‘Cooper pairs’ – combinations of two atoms that behave like a single particle to the outside.
Applying research to the Higgs particle
The Cooper pairs behave different from individual atoms as they move together and can do so without scattering on other atoms. This is the reason for the superconductivity.
Professor Dr Michael Köhl from the Physics Institute at the University of Bonn said: “This allowed us to create a state in which the pairs start to vibrate, and the quality of the superconductivity therefore oscillated very quickly: one moment the gas was a good superconductor, the next a bad one.”
This common oscillation of the Cooper pairs corresponds to the Higgs boson discovered at the CERN Accelerator in 2013.
The experiments allow an insight into certain physical properties of the Higgs particle. For example, the physicists hope that studies like these will enable them to better understand the decay of this particle.
The experiments also show a way to switch superconductivity on and off very quickly.
Superconductors normally try to remain in their conductive state for as long as possible. They can be deterred by heating, but this is a very slow process. The experiments show that in principle this can also be achieved a thousand times faster. This insight may open completely new applications for superconductors.