Back button not shown

Hi im using tab navigation in my project. When i go to the child state from its parent back button shows correctly but when i go to the same state from another tab the back button is not shown anymore.

This is how i defined my states:

.state(‘tab’, {
url : “/tab”,
abstract : true,
templateUrl : “templates/tabs.html”,
controller : ‘TabsCtrl’
})
.state(
‘tab.account’,
{
url : ‘/account/:opt’,
cache : false,
views : {
‘tab-account’ : {
templateUrl : ‘templates/tab-account.html’,
controller : ‘AccountCtrl’
}
}
})

.state(
‘tab.account.notificaciones’,
{
url : ‘/notificaciones’,
cache : false,
views : {
‘tab-account@tab’ : {
templateUrl : ‘templates/notificaciones.html’,
controller : ‘NotificacionesCtrl’
}
}
})