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Ultracold quantum dynamics: Spin-polarized K + K 2 collisions with three identical bosons or fermions

2005; American Physical Society; Volume: 71; Issue: 3 Linguagem: Inglês

10.1103/physreva.71.032722

1538-4446

Goulven Quéméner, Pascal Honvault, Jean–Michel Launay, Pavel Soldán, Daniel E. Potter, Jeremy M. Hutson,

Quantum Chromodynamics and Particle Interactions

We have developed a potential-energy surface for spin-polarized $\mathrm{K}(^{2}S)+{\mathrm{K}}_{2}(^{3}\ensuremath{\Sigma}_{u}^{+})$ collisions and carried out quantum dynamical calculations of vibrational quenching at low and ultralow collision energies for both bosons $^{39}\mathrm{K}$ and $^{41}\mathrm{K}$ and fermions $^{40}\mathrm{K}$. At collision energies above about $0.1\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$ the quenching rates are well described by a classical Langevin model, but at lower energies a fully quantal treatment is essential. We find that for the low initial vibrational state considered here $(v=1)$, the ultracold quenching rates are not substantially suppressed for fermionic atoms. For both bosons and fermions, vibrational quenching is much faster than elastic scattering in the ultralow-temperature regime. This contrasts with the situation found experimentally for molecules formed via Feshbach resonances in very high vibrational states.