Bright matter-wave solitons:
formation, dynamics and quantum reflection.
A.L. Marchant, M.M.H. Yu, S.A. Hopkins & S.L. Cornish
Funding: EPSRC Grant EP/F002068/1. EuroQUASAR Collaborative Research Project (EPSRC EP/G026602/1). Royal Society URF.
Solitons are self-focusing wave packets that can propagate over long distances without change in shape, and emerge from collisions unaltered. Bose-Einstein condensates (BEC) can support either "bright" or "dark" soliton solutions, depending on whether the atomic interactions are attractive or repulsive, respectively. The goal of this proposal is to study the formation, dynamics and quantum reflection of bright matter-wave solitons using Rb-85 condensates. Such solitons form well localised, self-stable atomic wave packets which are ideal for probing the spatial variation of an unknown force. In the future, precision measurements of the interactions between an atom and a solid surface may set new limits on short range corrections to gravity due to exotic forces beyond the Standard model.

The specific objectives of the project include:
  • The optimized production of Rb-85 condensates in the vicinity of a broad Feshbach resonance.
  • The investigation of the creation and stability of solitons for different trapping geometries.
  • The study of controlled collisions between two solitons as a function of the relative velocity and phase.
  • The demonstration of quantum reflection of solitons from a surface.
  • This work will assess the feasibility of using a "soliton interferometer" as a "tunable matter-wave surface probe", by separately demonstrating the initialization and readout of the interferometer and the ability to manipulate solitons in the vicinity of a surface. The project goals represent a "step change" in the study of bright matter-wave solitons and promise to deliver "solitons on demand" with controlled relative velocities and phases.

    Theoretical support:
    In addition to the in-house theory activities on solitons and BEC, the project benefits from strong collaborative links to other research groups. Theoretical support is provided through collaborations with Dr. Andrew Martin and Dr. Nick Parker at the University of Melbourne and Prof. Mark Fromhold at Nottingham University.
    Latest poster:        Latest results:
    June 2013November 2013December 2012
    We have observed quantum reflection of a soliton from an attractive potential formed by a tightly focused laser beam. See the news page for more details! A step closer to observing quantum reflection! A red detuned narrow light barrier of a waist of 2.7µm has been installed and tested. See news for more details!
    Content © Simon L. Cornish, Durham University 2007