prof. dr hab. Andrzej Drzewiński, UZ

Exotic Matter, pastries and the Nobel Prize in physics

It is said that matter can exist in one of three states, as a gas, liquid or solid, and the passage from one state to another occurs through a process called phase transition. But when one considers the matter formed in the shape of thin layers or wires, and strongly cooled, there is a whole collection of exotic states: superfluids, superconductors or magnets with the hidden order. In order to explain these unusual phenomena David Thouless, Duncan Haldane and Michael Kosterlitz have adapted to physics interesting methods belonging to the area of mathematics called topology. The object of its interest is the property of bodies that remain unchanged even under the deformation of objects. We can bend and squeeze them but tearing into parts or gluing is not permitted! The most interesting is that the properties of abstract shapes can be exploited to describe how very cold atoms and electrons behave. For example, they allowed physicists to show that in low temperatures certain properties of a very thin sheet that can conduct electricity should change in integer steps which is typical for properties rooted in topology. Other aspects of topology used to describe collections of many particles are still under development and widely studied.