Scientists realize a dynamic version of the quantum Hall effect in optical superlattices
The transport of particles is usually induced by applying an external gradient to a system. Water, for example, flows down a slope and electric current is generated by applying a voltage. But already in ancient times another way of generating a directional motion was known: by periodic modulation of a system, as can be seen in the famous Archimedes' screw. More than 30 years ago, the Scottish physicist David Thouless predicted that a similar phenomenon should also occur in quantum mechanical systems, so called topological pumping. A group of researchers from the Ludwig-Maximilians-Universität München and the Max Planck Institute of Quantum Optics, led by Professor Immanuel Bloch and in collaboration with the theoretical physicist Oded Zilberberg (ETH Zürich), have now successfully implemented such a topological charge pump with ultracold atoms in an optical lattice for the first time.