Researchers at NIST are studying collisions between ultra-cold atoms using magnetic fields and nano-eV colliders. They focus on understanding resonant phenomena in collisions among laser-coolable alkali-metal and lanthanide atoms in magnetic fields. The distribution of magnetic-field locations of these resonances is chaotic for magnetic lanthanide atoms like dysprosium, erbium, and thulium.
Understanding these atomic collisions is crucial for various research efforts at NIST, including atomic clocks, quantum-phase transitions, and Bose-Einstein condensates. Elastic collisions affect atomic transition energies and control the time scale for gases approaching thermodynamic equilibrium. Resonances in elastic collisions correspond to rapid changes in the cross section of atoms as a function of magnetic field and collision energy.
The researchers are currently investigating how to further understand and utilize resonances using ultracold-atom colliders. In ultracold gasses of dysprosium and erbium, the density of resonances as a function of magnetic field is exceptionally high over magnetic field strength ranges easily achievable in laboratory experiments. The distribution of resonances seems chaotic, and a quantitative understanding of resonance positions is still missing.
Keywords: Resonances, Collisional Processes, Ultra-cold Atoms, Lanthanide Atoms, Magnetic Fields
