Electrons can travel in groups of 2 or more at a time in 1D conducting systems

Adjacent reading: https://en.m.wikipedia.org/wiki/Cooper_pair

I’m trying to imagine what a 1D conductor looks like. just an atom? They call it a waveguide in the abstract.

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.

What does that mean for the uninitiated?

I guess that by itself, it doesn't mean much of anything. It is a very unusual setup on quantum mechanics, that will certainly lead to unusual properties, but that is a large "more research needed" situation.

If this leads to superconductors (a big if), those would be very high temperature ones.

It may also lead to some interesting magnets, maybe even useful as computers.