Autonomous entanglement engines

Generating and stabilizing entangled states is one of the upmost taks for achieving quantum information processing. Engineering, controlling and implementing feedback protocols between the quantum system and its environments have becoming state-of-the-art experimental techniques, at the heart of the development of quantum technologies. In this talk, I would like to take a step back, and simply discuss the possibility of exploiting out-of-equilibrium thermal environments, without any control, to generate quantum correlations among two or more qubits or higher-dimensional quantum systems. Remarkably, these setups can be viewed as thermal machines (the temperature bias between the environments acts as the thermodynamic force), operating exclusively in the quantum regime as their product is quantum correlations. Hence, they do not have a classical counterpart. Their dynamics and steady-state properties can be understood with theoretical tools appropriate for open quantum systems. I will review some of the most important results we obtained, with the goal of triggering new exciting experiments towards quantum thermal machines: the steady-state generation of multipartite entangled states, the existence of a critical heat current for certifying the presence of entanglement, and the control of the transient dynamics of these entanglement engines, with signatures of non-Hermitian physics in energy-based observables.

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