Well, seems that this is not the first question about this subject, but...
I know that we can use service or events for this, but there are many posts on the interne
Check out my post here about using services to share data between controllers: http://erikaugust.com/thoughts/angularjs-use-the-service-not-the-controller/?ws=so
There's a link to a JSFiddle example at the bottom of the blog post that will help.