Who told you that you can only create one view in a single window (and its XAML)?
This CodeProject article gives you the simple example of multiple views in one window:
MVVMLight Using Two Views[
^] (maybe not a very good article, but good enough for the purpose of out discussion).
Note, that I'm talking about multiple views, not multiple view models. Discussing mapping between view models and windows, as you are trying to do, is not a valid approach. View models are not visual things, views are, so first consider different views in one window, which is more than reasonable. After all, the application UI design with only one (non-modal) main window is one of the most convenient ones. You are not suggesting anything unusual.
As to the mapping between view models and views, this is a separate concern. Try to follow very reasonable discussion on multiple views and view models in this article:
http://www.wintellect.com/devcenter/jlikness/model-view-viewmodel-mvvm-explained[
^].
The author arguably insists that there is no need "to attach multiple viewmodels to a single view", but "a single viewmodel might be used by multiple views" — as part of "the chicken of the egg problem". Here, you also don't suggest anything unusual. As I could understand you, you want to have one view model for search view and one for the results view. It sounds quite reasonable.
—SA