Elimination of the Supersolid State Through Crystal Annealing

We have employed the torsional oscillator technique in the study of the supersolid state of solid 4He. We find that the supersolid state is not a universal property of solid helium, but in certain cases can be reduced or even eliminated through an annealing of the sample. We have also studied the supersolid in a number of cells with differing geometries, including cylindrical, cubic, and annular geometries, in an attempt to examine the possible influence of geometry on the stability of the supersolid state.