New Insights into the World of Quantum Materials

In Innsbruck a team of physicists led by Francesca Ferlaino experimentally observed how the anisotropic properties of particles deform the Fermi surface in a quantum gas. The work published in Science provides the basis for future studies on how the geometry of particle interactions may influence the properties of a quantum system. The Erbium Team (from left): Kiyotaka Aikawa, Albert Frisch, Simon Baier, Michael Mark, and Francesca Ferlaino (not pictured: Cornelis Ravensbergen) How a system behaves is determined by its interaction properties. An important concept in condensed matter physics for describing the energy distribution of electrons in solids is the Fermi surface, named for Italian physicist Enrico Fermi. The existence of the Fermi surface is a direct consequence of the Pauli exclusion principle, which forbids two identical fermions from occupying the same quantum state simultaneously. Energetically, the Fermi surface divides filled energy levels from the empty ones. For electrons and other fermionic particles with isotropic interactions - identical properties in all directions - the Fermi surface is spherical.