FisMat2017 - Submission - View

Abstract's title: Autonomous quantum machine for steady state entanglement generation via bath engineering
Submitting author: Francesco Tacchino
Affiliation: University of Pavia
Affiliation Address: Corso Strada Nuova, 65 - 27100 Pavia (PV) Dipartimento di Fisica: Via Bassi, 6 - 27100 Pavia
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: A. Auffèves (CNRS and Université Grenoble Alpes, Institut Néel, F-38042, Grenoble, France), M. F. Santos (Instituto de Fisica, Universidade Federal do Rio de Janeiro, RJ, Brazil), D. Gerace (Dipartimento di Fisica, Università di Pavia, via Bassi 6, I-27100 Pavia, Italy)

We propose an elementary quantum device able to generate a signicant amount of steady state entanglement without the need for any coherent driving, thus showing that entanglement can be created relying only on incoherent energy sources. It consists of a pair of incoherently driven qubits coupled to a quantised electromagnetic cavity mode: under specic conditions, the cavity mode provides an effective channel for mutual qubits interaction, which can be interpreted as dissipative bath engineering. Heat owing through the system helps maintaining the non-local nature of the steady state, which is quantied by the negativity of the density matrix and can reach steady state values up to 20% of the theoretical maximum. We also provide a description in terms of eective temperatures, which means that the device can work as a nanoscale thermal machine. More generally, this setup belongs to the class of autonomous quantum machines, since it can operate without any accurate external control on the dynamics. With respect to the existing literature, our implementation explicitly provides a technique to structurally obtain a stable eective qubit-qubit coupling. Moreover, we point out the possible role of non-local baths as a key ingredient for further developments in the design of quantum engines. Special attention is paid to realistic parameters in view of future tests and realisations in solid state systems.