Classical and quantum reflection of bright matter-wave solitons

We report the controlled formation of a bright matter-wave soliton\footnote{A. L. Marchant et al., Nat. Commun. 4, 1865 (2013)} from a Bose--Einstein condensate of $^{85}$Rb\footnote{A. L. Marchant et al., Phys. Rev. A. 85, 053647 (2012)}. We demonstrate the reflection of the soliton from a broad repulsive Gaussian barrier and contrast this to the case of a repulsive condensate, in both cases finding excellent agreement with theoretical simulations using the 3D Gross-Pitaevskii equation. Using a tightly focussed red-detuned light sheet, we create a narrow attractive potential well, comparable in the narrow direction to the size of the soliton. Using a low incident velocity, we observe a splitting of the atomic wavepacket when it reaches the well, resulting in quantum reflection of $\sim$25\% of the atoms\footnote{A. L. Marchant et al., arXiv 1507.04639 (2015)}. In addition, a smaller fraction of atoms ($\sim$10\%) become trapped at the well. These results pave the way for new experimental studies of bright matter-wave soliton dynamics to elucidate the wealth of existing theoretical work and to explore an array of potential applications such as the study of short-range atom-surface potentials\footnote{S. L. Cornish et al., Physica D 238, 1299 (2009)}.