  We demonstrate reduction of the dc polarizability of Cesium atom Rydberg
states in a 77 K environment utilizing microwave field dressing. In particular
we reduce the polarizability of $52P_{3/2}$ states which have resonances at
5.35 GHz to $51D_{5/2}$, suitable for interfacing Rydberg atoms to
superconducting resonators in a cryogenic environment. We measure the
polarizability of the Rydberg states using Magneto-Optical-Trap (MOT) loss
spectroscopy. Using an off-resonant radio-frequency (RF) dressing field
coupling $52P_{3/2}$ and $51D_{5/2}$ we demonstrate a reduction in dc
polarizability of the $ 52P_{3/2}$ states over 80$\%$. Experimental findings
are in good agreement with a numerical model of the atom-dressing field system
developed using the Shirley-Floquet formalism. We also demonstrate that the dc
polarizability reduction is highly anisotropic, with near total nulling
possible when the dc and dressing fields are aligned, but only a factor of two
reduction in polarizability when the fields are orthogonal. These results may
aid in stabilizing Rydberg resonances against varying dc fields present near
surfaces, enabling advancement in the development of hybrid Rydberg atom -
superconducting resonator quantum gates.
