arXiv:1507.04639 · Physical Review A
Quantum reflection of bright solitary matter waves from a narrow attractive potential
A. L. Marchant, T. P. Billam, M. M. H. Yu, Ana Rakonjac, J. L. Helm, Juan Polo, Christoph Weiß, S. A. Gardiner, Simon L. Cornish
Abstract
We report the observation of quantum reflection from a narrow attractive potential using bright solitary matter waves formed from a $^{85}\mathrm{Rb}$ Bose-Einstein condensate. We create the attractive potential using a tightly focused, red-detuned laser beam, and observe reflection of up to 25% of the atoms, along with the confinement of atoms at the position of the beam. We show that the observed reflected fraction is much larger than theoretical predictions for a simple Gaussian potential well. A more detailed model of bright soliton propagation, accounting for the generic presence of small subsidiary intensity maxima in the red-detuned beam, suggests that these small intensity maxima are the cause of this enhanced reflection.