Does this feature exist in Emacs orgmode core?

Yes

Orgmode link

https://orgmode.org/manual/Citation-handling.html
https://orgmode.org/manual/Citations.html

Feature value

Introduced in orgmode 9.5 (so fairly recent), this is most commonly used in academia with a bibliography file.

Additional context

There's a companion function, `org-cite-insert, where one can then insert and edit citations.

We discussed this in the org-roam plugin discussion. This isn't a requirement for the initial version of org-roam.nvim, but I wanted to document it here as a request because it is part of core orgmode.