Quantum Grey Solitons in Confining Potentials – Trapped Lieb II mode
Dimitry Gangardt, University of Birmingham
We define and study hole-like excitations (the Lieb II mode) in a weakly interacting Bose liquid subject to external confinement. These excitations are obtained by semiclassical quantization of grey solitons propagating on top of a Thomas-Fermi background similarly to the uniform case. Radiation of phonons by an accelerated gray soliton leads to a finite lifetime of these excitations. We calculate the life-time of grey solitons and show that, for a large number of trapped atoms, most of the Lieb II levels can be experimentally resolved.
D. C. Wadkin-Snaith and D. M. Gangardt, Phys. Rev. Lett. 108, 085301 (2012)