Is spatial distance just a classical concept?

[geordief]

I am learning the coherence of a quantum system  can be maintained over very great distances and this leads me to ask the question in the Title of the thread.

 

In that example distance is less important than the number of potential or actual  interactions with an entangled system?

Could that  be considered as a kind of "distance" in quantum physics?

 

If not ,what is the concept of distance in quantum physics ? Just the same as in classical physics?

Edited October 16, 2021 by geordief

[swansont]

The distance variable is part of the Schrödinger equation and solution for e.g. hydrogen; the radial wave function has “r” in it.

While position isn’t well-defined owing to the wave nature on this scale, distance still matters. 

[Markus Hanke]

It should also be mentioned that the spacetime interval of Special Relativity is a crucial building block of quantum field theory. You couldn’t have the Standard Model without SR.