The Templar Archives is a structure on the Protoss Technology Tree that unlocks the High Templar spell caster unit and the Psionic Storm upgrade. The Templar Archives requires a Twilight Council before it can be warped in.
Like most Protoss structures, the Templar Archives can only be warped in at a location powered by the Psionic Matrix. It can only research upgrades while it remains within the Matrix, otherwise it becomes unpowered and cannot function. However, even an unpowered Templar Archives still allows the creation of High Templar.