Cross-Realm Sign-On


I have use case and i want advice from experts here.
I have two realms, realm A & B both realms have different applications.

User Story : User have logged in to application A in realm-A, no user want to go to application B in realm-B but users dont want to login

I want to implement a solution that allows users to navigate from application A (logged in) to application B with login again. Can i achieve this cross realm scenario.

Please advice