Using quantum erasure to exorcize Maxwell's demon: III. Implementation

We present a negentropy quantum heat engine [M.O. Scully, Phys. Rev. Lett. 87 (2001) 220601] which uses a Stern–Gerlach apparatus as a quantum sorter and a pair of Raman pulses in order to adiabatically transfer population from one hyperfine ground sublevel to another. Work is produced in a microwave cavity by exploiting the energy of an atom's internal degrees of freedom. Such a scheme may be possible to implement under realistic experimental conditions.