Stateprovider $state not working in ionic framework

I am trying to set my login page as initial state. When user clicks on register user, I am doing $state.go (in controller) to register page from where user should be able to come back to login page.

angular.module('starter', ['ionic', 'starter.controllers','ui.router']).config(['$stateProvider','$urlRouterProvider',function($stateProvider, $urlRouterProvider).state('login',{
      url:"/login",

      templateUrl:'templates/login.html',
      controller:'LoginCtrl'
  })
  .state('login.registerUser',{

      url:"/registerUser",
      views: {
          'menuContent' :{
              templateUrl:'templates/registerUser.html',
              controller:'registerCtrl'
          }
      }

  })

controller

.controller('LoginCtrl', ['$scope', 'Auth', '$state', '$ionicPlatform','SessionService', function($scope, Auth, $state, $ionicPlatform, SessionService) {
$ionicPlatform.ready(function() {
    window.scope = $scope;
    $scope.credentials = {username: "", password: "", remember: ""};
    $scope.userData = {username: "", id: ""};

    var utils = {
        createNewUser:function(){
            console.log('here');//I CAN SEE THIS 
            $state.go('login.registerUser');//NOTHIN HAPPENS
        }
    };
    $scope.goToRegistration = utils.createNewUser;


});

}])

But it is not doing anything. Please Help

Your syntax is a little messed up. Try this:

angular.module('starter', ['ionic', 'starter.controllers','ui.router'])
.config(['$stateProvider','$urlRouterProvider',function($stateProvider, $urlRouterProvider){
$stateProvider
.state('login',{
      url:"/login",

      templateUrl:'templates/login.html',
      controller:'LoginCtrl'
})
.state('login.registerUser',{

  url:"/registerUser",
  views: {
      'menuContent' :{
          templateUrl:'templates/registerUser.html',
          controller:'registerCtrl'
      }
  }

})
});

I am not sure about ionic but in general angular app when you define a child state you need to have a nested ui-view in your page or use a named view, View Names can be Relative or Absolute Names check this from docs and this plunkr

<p>login</p><div ui-view></div>  //login template
<p>registerUser</p> //registerUser template

for nested ui view