Abstract
We explore bright soliton solutions of ultracold Bose-Fermi gases, showing that the presence of -wave interactions can remove the usual collapse instability and support stable soliton solutions that are global energy minima. A variational model that incorporates the relevant - and -wave interactions in the system is established analytically and solved to probe the dependencies of the soliton stationary states on key experimental parameters. Under attractive -wave interactions, bright solitons exist only as metastable states susceptible to collapse. Remarkably, the presence of repulsive -wave interactions alleviates this collapse instability. This dramatically widens the range of experimentally achievable soliton solutions and indicates greatly enhanced robustness. While we focus specifically on the boson-fermion pairing of Rb and K, the stabilization inferred by repulsive -wave interactions should apply to the wider remit of ultracold Bose-Fermi mixtures.
- Received 17 August 2011
DOI:https://doi.org/10.1103/PhysRevA.85.013604
©2012 American Physical Society