asp.net mvc 5.1, asp.net identity 2.0, Request.IsAuthenticated problem

I created a project using asp.net mvc 5.1, asp.net identity 2.0. After I deploy it to IIS, when I go to secure page 'https://www.domain.com/Account/Login', after login,  if I go to https://www.domain.com. Request.IsAuthenticated  return true on _LoginPartial.cshtml page, but go to http://www.domain.com, always return false.
I don't know what's wrong. thanks for help