Nonrelativistic spatiotemporal quantum reference frames

Abstract

Quantum reference frames have attracted renewed interest recently, as their exploration is relevant and instructive in many areas of quantum theory. Among the different types, position and time reference frames have captivated special attention. Here, we introduce and analyze a nonrelativistic framework in which each system contains an internal clock, in addition to its external (spatial) degree of freedom and, hence, can be used as a spatiotemporal quantum reference frame. We present expressions for expectation values and variances of relevant observables in different perspectives, as well as relations between these quantities in different perspectives in scenarios with no interactions. In particular, we show that even in these simple scenarios, the relative uncertainty between clocks affects the relative spatial spread of the systems.

Typos corrected. Author's accepted version

References in corpus (4)

• Reference frames, superselection rules, and quantum information
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• A model of quantum spacetime

Cited by in corpus (5)

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• Generalised second law beyond the semiclassical regime
• Crossed products and quantum reference frames: on the observer-dependence of gravitational entropy
• Gravitational null rays: Covariant Quantization and the Dressing Time
• Spacetime quantum mechanics for bosonic and fermionic systems