A three-eighths upper bound on the stabilizer-rank exponent of face-center magic states

We give an explicit construction proving that the exact stabilizer rank of m copies of the qubit face-center magic state is O(2 3m/8). Two symmetry-related fifteen-term identities combine into a twenty-four-term decomposition at twelve copies. The balanced structure of this decomposition yields a substitution that adds eight copies at a cost of eight terms per existing term. The resulting bound γ T at most 3/8 improves the previously published exponent 2(3)/4.