Josephson maser and heat transport in dissipative open quantum systems

This project is devoted to study the heat transport in dissipative open quantum systems. The main scientific and technological goals are: (i) to study the effect of anharmonicity in the heat transport in a dissipative open quantum system; and (ii) to realize a Josephson maser, to demonstrate coherent emission of microwave photons driven by a superconducting transmon qubit. To study heat transport in the quantum limit we propose a device with a qubit coupled to two resonators, each terminated by mesoscopic normal-metal reservoirs acting as source and drain thermal baths. When a thermal bias is applied across the system, the heat is transmitted between the two mesoscopic reservoirs via the qubit, and dissipated in the drain reservoir. With a sufficiently electron temperature in the heated reservoir, the population inversion prerequisite will be satisfied, and the proposed system will work as a maser, allowing for efficient on-chip generation of coherent microwave photons at low temperatures. The proposed system provides a platform to study the heat transport in dissipative open quantum systems, and both spontaneous and stimulated microwave emission. Therefore, it will contribute a pioneering technology to the field of quantum technology, and environment engineering for quantum technologies, in addition to developing a promising tool for quantum thermodynamics. The fundamental knowledge of quantum physics targeted in this proposal will be immediately applicable in several applied fields; the microelectronics industry, quantum computers, and communication sectors, and it will have a great impact on society both in Europe and globally.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 843706.