Splitting and recombination of bright-solitary-matter waves

• Published in: Communications physics Vol. 3; no. 1
• Main Authors: Wales, Oliver J., Rakonjac, Ana, Billam, Thomas P., Helm, John L., Gardiner, Simon A., Cornish, Simon L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.03.2020; Nature Publishing Group
• Subjects: 639/766/36/1125; 639/766/483/3924; Bose-Einstein condensates; Interference; Interferometers; Interferometry; Matter waves; Physics; Physics and Astronomy; Solitary waves; Splitting; Stability; Wave packets; Waveguides
• ISSN: 2399-3650; 2399-3650
• DOI: 10.1038/s42005-020-0320-8

Atomic Bose–Einstein condensates confined in quasi-1D waveguides can support bright-solitary-matter waves when interatomic interactions are sufficiently attractive to cancel dispersion. Such solitary-matter waves are excellent candidates for highly sensitive interferometers, as their non-dispersive nature allows them to acquire phase shifts for longer times than conventional matter-wave interferometers. In this work, we demonstrate experimentally the splitting and recombination of a bright-solitary-matter wave on a narrow repulsive barrier, realizing the fundamental components of an interferometer. We show that for a sufficiently narrow barrier, interference-mediated recombination can dominate over velocity-filtering effects. Our theoretical analysis shows that interference-mediated recombination is extremely sensitive to the barrier position, predicting strong oscillations in the interferometer output as the barrier position is adjusted over just a few micrometres. These results highlight the potential of soliton interferometry, while putting tight constraints on the barrier stability needed in future experimental implementations. Bright solitary waves are wavepackets that propagate without dispersion and have been under intense investigation in a variety of settings, including Bose–Einstein condensates (BEC), with a view of realizing a matter-wave interferometer. The authors present experimental and theoretical results on a bright-matter-wave soliton from a BEC, and observe splitting and recombination at a barrier potential enabling them to place constraints on the barrier stability needed to implement soliton interferometry.