Hybrid quantum systems can often be described in terms of polaritons. These
are quasiparticles formed of superpositions of their constituents, with
relative weights depending on some control parameter in their interaction. In
many cases, these constituents are coupled to reservoirs at different
temperatures. This suggests a general approach to the realization of
polaritonic heat engines where a thermodynamic cycle is realized by tuning this
control parameter. Here we discuss what is arguably the simplest such engine, a
single qubit coupled to a single photon. We show that this system can extract
work from feeble thermal microwave fields. We also propose a quantum
measurement scheme of the work and evaluate its back-action on the operation of
the engine.Comment: 8 pages, 4 figures, new contents adde
