Soliton Interferometry with Very Narrow Barriers Obtained from Spatially Dependent Dressed States.

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.