arXiv subjects

Silke Ospelkaus

Publications and source records attributed to Silke Ospelkaus.

21 records · Page 2Linked to original sources

arXiv2017

Laser and Fourier transform spectroscopy of KCa

KCa was produced in a heatpipe oven and its thermal emission spectrum around 8900 cm$^{-1}$ was recorded by a high resolution Fourier transform spectrometer. In addition, many selected transitions of this spectrum between deeply bound vibrational levels of the $\mathrm{X}(1)^2Σ^+$ and $(2)^2Σ^+$ states were studied using laser excitation to facilitate the assignment of the lines. The ground state is described for $v^{\prime\prime} =$ 0 - 5 and the $(2)^2Σ^+$ state for $v^{\prime} =0$ - 8 with rotational levels up to 175. For both states, Dunham coefficients, spin-rotation parameters and potential energy curves are derived.

physics.atom-ph↗

arXiv2015

Ultracold Chemistry and its Reaction Kinetics

We study the reaction kinetics of chemical processes occurring in the ultracold regime and systematically investigate their dynamics. Quantum entanglement is found to play a key role in driving an ultracold reaction towards a dynamical equilibrium. In case of multiple concurrent reactions Hamiltonian chaos dominates the phase space dynamics in the mean field approximation.

quant-ph↗

arXiv2008

Heteronuclear molecules in an optical lattice: Theory and experiment

We study properties of two different atoms at a single optical lattice site at a heteronuclear atomic Feshbach resonance. We calculate the energy spectrum, the efficiency of rf association and the lifetime as a function of magnetic field and compare the results with the experimental data obtained for K-40 and Rb-87 [C. Ospelkaus et al., Phys. Rev. Lett. 97, 120402 (2006)]. We treat the interaction in terms of a regularized delta function pseudopotential and consider the general case of particles with different trap frequencies, where the usual approach of separating center-of-mass and relative motion fails. We develop an exact diagonalization approach to the coupling between center-of-mass and relative motion and numerically determine the spectrum of the system. At the same time, our approach allows us to treat the anharmonicity of the lattice potential exactly. Within the pseudopotential model, the center of the Feshbach resonance can be precisely determined from the experimental data.

cond-mat.other↗