Breaking quantum control limits: Two-level systems can now be directionally pumped beyond the optical-Bloch bound by treating the excitation source as quantum. The asymmetric dissipative channels arise from source second moments—not coherent drive.

Breaking quantum control limits: Two-level systems can now be directionally pumped beyond the optical-Bloch bound by treating the excitation source as quantum. The asymmetric dissipative channels arise from source second moments—not coherent drive.