Entanglement generation with autonomous quantum thermal machines (or how quantum thermal machines clearly outperform classical ones

Entanglement is a key phenomenon distinguishing quantum from classical physics, and is a paradigmatic resource enabling many applications of quantum information science. Generating and maintaining entanglement is therefore a central challenge. Decoherence caused by unavoidable interactions of a system with its environment generally degrades entanglement, and significant effort is invested in minimising the effect of such dissipation processes in experiments. However, dissipation can also be advantageous, and may in fact be exploited for generating entangled quantum states under the right conditions. This research direction has given rise to the development of reservoir engineering, but also to autonomous quantum thermal machines. In this talk, I will present the functioning  of one of the simplest thermal machine that can generate entanglement, a machine that we proposed with my colleagues in Geneva and Vienna. This machine makes use of an out-of-equilibrium situation to maintain entanglement in the steady-state regime. Remarkably, these results have motivated experimentalists and I will describe an on-going experiment done at ENS Lyon within Circuit QED. 
However, this thermal machine does not allow the generation of entanglement strong enough to violate Bell-type inequalities, necessary for instance for device-independent quantum information processing. Motivated by this limitation, we have developed a new type of thermal machine and I will show you how maximally entangled states can be generated in a heralded way, thanks to the use of local filters. Of particular interest, this machine can be generalized to arbitrary dimension, allowing for the generation of arbitrary-dimension singlet states and of multipartite entangled states, such as the GHZ, the W and cluster states.
These novel quantum thermal machines are emblematic to illustrate how autonomous quantum thermal machines, running thanks to purely dissipative processes, outperform their classical counterparts. This research also highlights the importance of quantum transport properties to run quantum thermal machines. These examples illustrate the power of thermal machines to create genuine quantum resources.