Related Experiment Video
Updated: Aug 8, 2026

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Localization of bosonic atoms by fermionic impurities in a three-dimensional optical lattice
S Ospelkaus1, C Ospelkaus, O Wille
1Institut für Laserphysik, Luruper Chaussee 149, 22761 Hamburg, Germany.
Abstract:
We observe a localized phase of ultracold bosonic quantum gases in a 3-dimensional optical lattice induced by a small contribution of fermionic atoms acting as impurities in a Fermi-Bose quantum gas mixture. In particular, we study the dependence of this transition on the fermionic (40)K impurity concentration by a comparison to the corresponding superfluid to Mott-insulator transition in a pure bosonic (87)Rb gas and find a significant shift in the transition parameter. The observed shift is larger than expected based on a simple mean-field argument, which indicates that disorder-related effects play a significant role.
Related Concept Videos
Lattice Centering and Coordination Number
Types of Unit Cells
Imagine taking a large number of identical...
The de Broglie Wavelength
Hybridization of Atomic Orbitals I
Hybridization of Atomic Orbitals II
Imperfections in Crystal Structure: Stoichiometric Point Defects
Electronic Structure of Atoms
An atom comprises protons and neutrons, which are contained inside the dense, central core called the nucleus, with electrons present around the nucleus. Taking into account the wave–particle duality of electrons and the uncertainty in position around the nucleus, quantum mechanics provides a more accurate model for the atomic structure. It describes atomic orbitals as the regions around the nucleus where electrons of discrete energy exist, characterized by four quantum numbers: n, l, ml, and...

