Fig. 2.

Measured extracted power (normalized by a quantum of energy $h{f}_S$) for step 3 as a function of time during the pulse at $f_S$. Blue, orange, and red symbols and error bars correspond to an initial thermalized system at temperatures $T=$0.17 K, 0.40 K, and above 8 K (see Inset for initial Bloch vectors). Green symbols correspond to an initial quantum superposition obtained by a $3\pi /2$-pulse acting on the system at 0.10 K. Solid lines result from a numerical simulation with no fit parameters and match the measurements well. (A) The demon memory state ${\rho }_{{\alpha }_{in}}$ contains $\overline{n}=9$ photons when encoding a system in ${|g⟩}_S$. (B) Same as A for an ignorant demon ($\overline{n}=0$ in step 2).