Astafiev, O. V. and Abdumalikov, A. A. and Zagoskin, A. M. and Pashkin, Yuri and Nakamura, Y. and Tsai, J. S. (2010) Ultimate On-Chip Quantum Amplifier. Physical review letters, 104 (18). -. ISSN 0031-9007
Full text not available from this repository.Abstract
We report amplification of electromagnetic waves by a single artificial atom in open 1D space. Our three-level artificial atom-a superconducting quantum circuit-coupled to a transmission line presents an analog of a natural atom in open space. The system is the most fundamental quantum amplifier whose gain is limited by a spontaneous emission mechanism. The noise performance is determined by the quantum noise revealed in the spectrum of spontaneous emission, also characterized in our experiments.