General Relativistic Decoherence with Applications to Dark Matter Detection

Understand

Quantum mechanics allows for states in macroscopic superpositions, but they ordinarily undergo rapid decoherence due to interactions with their environment.

• A system that only interacts gravitationally, such as an arrangement of dark matter (DM), may exhibit slow decoherence.
• In this Letter, we compute the decoherence rate of a quantum object within general relativity, focusing on superposed metric oscillations; a rare quantum general relativistic result.
• For axion DM in a superposition of the field's phase, we find that DM in the Milky Way is robust against decoherence, while a spatial superposition is not.