1205.3195 (C. Jess Riedel)

Decoherence and the Quantum Detection of Classically Undetectable
Phenomena    [PDF]

C. Jess Riedel

I consider the general problem of exploiting quantum mechanics to detect weak particles and forces. A phenomenon is detectable using classical methods if and only if the effective Hamiltonian coupling it to normal matter does not commute with the classically preferred basis. Classically undetectable phenomena can still be observed, but they require coherent superpositions and measurements which do not commute with the preferred basis. The Aharonov-Bohm effect, the shot noise limit, and the standard quantum limit are special cases of this general idea. I propose using matter-wave interferometry to directly detect hypothetical new particles, such as sub-MeV dark matter, that transfer negligible momentum when colliding with normal matter. The coherent control of planck-mass superpositions could also enable the detection of relic neutrinos, fifth forces, and even gravitons.

View original: http://arxiv.org/abs/1205.3195