  Optical potentials have been a versatile tool for the study of atomic motions
and many-body interactions in cold atoms. Recently, optical subwavelength
single barriers were proposed to enhance the atomic interaction energy scale,
which is based on non-adiabatic corrections to Born-Oppenheimer potentials.
Here we present a study for creating a new landscape of non-adiabatic
potentials--multiple barriers with subwavelength spacing at tens of nanometers.
To realize these potentials, spatially rapid-varying dark states of atomic
$\Lambda$-configurations are formed by controlling the spatial intensities of
the driving lasers. As an application, we show that bound states of very long
lifetimes on the order of seconds can be realized. Imperfections and
experimental realizations of the multiple barriers are also discussed.
