Testing the universality of free fall with a two species atomic gravimeter

In the CAPRICE experiment, the authors employ atom interferometry to compare the free fall of potassium and rubidium atoms with a differential atomic gravimeter. This leads to a precision test of the universality of free fall with two quantum objects. The paper presents the first results with the single species rubidium gravimeter and show the progress of the system update to trap and manipulate potassium atoms. The progress in working with an optical dipole trap at a wavelength of 1960 nm was also presented.