2010/07/31 by Timur V. Tscherbul, T. V. Tscherbul, J. Klos +13
Chemistry · Physics and Astronomy · #Ab initio #Atom (system on chip) #Atomic and Subatomic Physics Research #Atomic physics #Cold Atom Physics and Bose-Einstein Condensates #Dipole #Physics #Quantum mechanics #Relaxation (psychology) #Scattering #Spectroscopy and Laser Applications #Spin (aerodynamics) #Thermodynamics #physics.atom-ph
paper · pdf · doi:10.1103/physreva.82.042718
published as Phys. Rev. A 82, 042718 (2010) · 48 pages, 17 figures, 3 tables
openalex publication_date 2010/10/26 · arxiv created 2011/03/04 · arxiv updated 2011/03/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We report a combined experimental and theoretical study of collision-induced dipolar relaxation in a cold spin-polarized gas of atomic nitrogen (N). We use buffer gas cooling to create trapped samples of 14N and 15N atoms with densities (5\ifmmode±\else\textpm\fi2)\ifmmode×\else\texttimes\fi1012 cm^\ensuremath-3 and measure their magnetic relaxation rates at milli-Kelvin temperatures. These measurements, together with rigorous quantum scattering calculations based on accurate ab initio interaction potentials for the 7\ensuremathΣu+ electronic state of N2 demonstrate that dipolar relaxation in N+N collisions occurs at a slow rate of ~10^\ensuremath-13 cm3/s over a wide range of temperatures (1 mK to 1 K) and magnetic fields (10 mT to 2 T). The calculated dipolar relaxation rates are insensitive to small variations of the interaction potential and to the magnitude of the spin-exchange interaction, enabling the accurate calibration of the measured N atom density. We find consistency between the calculated and experimentally determined rates. Our results suggest that N atoms are promising candidates for future experiments on sympathetic cooling of molecules.