For OneToOne I do not see relationship tables often.
Just like this posts shows (
JPA @OneToOne Unidirectional and Bidirectional), It just describes a relationship without a need of a Join Table.
I think it is not a good approach to have a join table because the default fetch for OneToOne is EAGER, and it would required more joins to finish when searching for an entity if you do not set as LAZY.
If you do set as Lazy it would require one more join than the regular approach.