No such actionThere is possible. Otherwise one would have a free action on a spherebit of lower dimension linkinga disconnect between the fixed point settitle and the actual question. But such an action would giveUsually a freesemifree action is one in which the only isotropy groups are the trivial group and the whole group. The actions with only finite isotropy groups, in the body of $G=\mathbf{Z}_p\times \mathbf{Z}_p$your question, are often called ``pseudofree'' actions. If a torus were to act pseudofreely on a sphere, violating then a subgroup of the known factform $G=\mathbf{Z}_{p}\times \mathbf{Z}_{p}$ for some prime $p$ would act freely on the sphere. It is well-known that such a finitethe latter group cannot act freely on a finite complex with the homology of a sphere. Such because such an action of $G$ can be shown by a splicing argument to provide a periodic resolution of $\mathbf{Z}$ as a trivial $\mathbf{Z}[G]$-module, violating the factwould imply that thisthe group does not havehas periodic cohomology, which (by the Kunneth formula)$G$ does not. See Bredon's book Introduction to Compact Transformation Groups, for example.
Rewrote the answer in part to clarify terminology and to give a reference.
Allan Edmonds
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