Bright solitons in atomic Bose-Einstein condensates are strong candidates for high precision matter-wave interferometry, as their inherent stability against dispersion supports long interrogation times. An analog to a beam splitter is then a narrow potential barrier. A very narrow barrier is desirable for interferometric purposes, but in a typical realization using a blue-detuned optical dipole potential, the width is limited by the laser wavelength. We investigate a soliton interferometry scheme using the geometric scalar potential experienced by atoms in a spatially dependent dark state to overcome this limit. We propose a possible implementation and numerically probe the effects of deviations from the ideal configuration.
Grimshaw, C. L., Billam, T. P., & Gardiner, S. A. (2022). Soliton Interferometry with Very Narrow Barriers Obtained from Spatially Dependent Dressed States. Physical Review Letters, 129(4), Article 040401. https://doi.org/10.1103/physrevlett.129.040401