1D is a line or vector, I believe. A waveguide for atoms would probably still be considered 1D I guess.
that sounds better. I thought a point was 1D, a line was 2D thinking of a plot with X and Y axis, and a surface was 3D - but a totally flat surface would be 2D, and a totally straight line i guess is 1D. a point must be 0D.
Yeah, in this case dimensionality would refer to degrees of freedom, not the cardinality of the space.