My best published idea is decoherence detection. Large quantum superpositions are sensitive to softly interacting particles and forces that cannot be detected by any other means. Relevant papers:
- “Decoherence from classically undetectable sources: Standard quantum limit for diffusion.” Summary: Some sources of decoherence cannot be detected with classical experimental methods. PRA 92, 010101(R) (2015) [arXiv:1504.03250].
- “Direct detection of classically undetectable dark matter through quantum decoherence.” Summary: Matter interferometers and other large spatial superpositions will be sensitive to (otherwise invisible) low-mass dark matter. PRD 88, 116005 (2013) [arXiv:1212.3061].