Taken from this page dated March 1 2013
"SP controls can only be used on SP hosted pages. Currently the only control designed from the ground up to be consumed on all page types (provider-hosted, auto-hosted or sp hosted) is the chrome control."
and another post from an MSFT
"I've consulted with several colleagues and the consensus seems to be that SharePoint's client side people picker, which is JavaScript, cannot be used in a provider-hosted app. The reason is that there's no way to get a client context on a remote web page. You mention the TokenHelper.cs which is managed code, not JavaScript. I have a question pending with the product team to see if there's anyway to get the context with managed code and pass it to JavaScript. I didn't want you to have to wait any longer for an answer."