Changing quantum reference frames

Understand

We consider the process of changing reference frames in the case where the reference frames are quantum systems.

• We find that, as part of this process, decoherence is necessarily induced on any quantum system described relative to these frames.
• We explore this process with examples involving reference frames for phase and orientation.
• Quantifying the effect of changing quantum reference frames serves as a first step in developing a relativity principle for theories in which all objects including reference frames are necessarily quantum.