I think this would rather be a question for the English-French forum, and that "portail" would also work in French.
I am not sure this warrants another sense in the dictionary but I'll let the enbase editors decide.
Thank you for your message. I've had a look at a few monolingual dictionaries, and none of them has a separate definition for a science fiction meaning of portal. Essentially, I think it is still a gateway or entrance (just to somewhere else entirely, instead of a building or whatever that's right in front of you). So I think an additional sense isn't necessary, but I have added a more sci-fi sentence. That will go to our translation teams for review. Once that's been done, it will appear in the dictionaries the next time they are updated.