Should client-side development using frameworks such as Ember.js be separated from the Back-end development using Rails?

I'm new to front-end development and I'm thinking about separating the code into two projects, one for front-end (using Ember.js) and another for backend (Ruby on Rails) which these two sides would talk to each others using JSON and REST API. However, I'm not sure if this is the path I should take since there is a gem called 'ember-rails' and I'm not sure if I should use it to make my development easier. I'm quite familiar with Rails, but I have zero experience in EmberJS. Please throw me some ideas what should I do to make my development more appropriate. Thank you