  The generation of genuine multipartite entangled states is challenging in
practice. Here we explore a new route to this task, via autonomous entanglement
engines which use only incoherent coupling to thermal baths and
time-independent interactions. We present a general machine architecture, which
allows for the generation of a broad range of multipartite entangled states in
a heralded manner. Specifically, given a target multiple-qubit state, we give a
sufficient condition ensuring that it can be generated by our machine. We
discuss the cases of Greenberger-Horne-Zeilinger, Dicke and cluster states in
detail. These results demonstrate the potential of purely thermal resources for
creating multipartite entangled states useful for quantum information
processing.
