02249nas a2200133 4500008004100000245007900041210006900120260001500189520179100204100002401995700001902019700001902038856005802057 2020 eng d00aPosition Space Decoherence From Long-Range Interaction With Background Gas0 aPosition Space Decoherence From LongRange Interaction With Backg c06/05/20203 a

 Experiments in matter wave interferometry and optomechanics are increasing the spatial extent of wavefunctions of massive quantum systems; this gives rise to new sources of decoherence that must be characterized. Here we calculate the position space decoherence of a quantum particle due to interaction with a fluctuating classical background gas for several different force laws. We begin with the calculation of this effect for the Newton potential. To our knowledge, this calculation has not been done before. We then solve the same problem in the case of a Yukawa interaction, which interpolates between our long-range force result and the well-studied formula for collisional decoherence from a contact interaction. Unlike the contact interaction case, where the decoherence rate becomes independent of distance for large quantum particle separations, we observe that a long-range interaction leads to quadratic scaling of the decoherence rate with distance even at large separations. This work is relevant to the generation of massive superposition in optomechanical and atom beam experiments, and to conclude we comment on the use of this decoherence signal for gravitational detection of dark matter. 

1 aKunjummen, Jonathan1 aCarney, Daniel1 aTaylor, J., M. uhttp://meetings.aps.org/Meeting/DAMOP20/Session/S08.5