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MA: Fachverband Magnetismus
MA 33: Transport: Quantum Coherence and Quantum Information Systems - Experiment (jointly with MA, HL)
MA 33.12: Talk
Wednesday, March 22, 2017, 12:30–12:45, HSZ 03
Near quantum-limited amplification and conversion based on a voltage-biased Josephson junction — •Salha Jebari1,2, Florian Blanchet1,2, Romain Albert1,2, Dibyendu Hazra1,2, and Max Hofheinz1,2 — 1CEA, Grenoble,France — 2Université Grenoble Alpes, Grenoble, France
Recent experiments with superconducting circuits consisting of a DC voltage-biased Josephson junction in series with a resonator have shown that a tunneling Cooper pair can emit one or several photons with a total energy of 2e times the applied voltage. We present microwave reflection measurements on the device in , indicating that amplification is possible with a simple DC voltage-biased Josephson junction. We also show that this amplification adds noise close to the limit set by quantum mechanics for phase preserving amplifiers. For low Josephson energy, transmission and noise emission can be explained within the framework of P(E) theory of inelastic Cooper pair tunneling and are related to the fluctuation dissipation theorem (FDT). We also experimentally demonstrate, by controlling the applied DC voltage, that our device can act as both an amplifier and a frequency converter. Combined with a theoretical model, our results indicate that voltage-biased Josephson junctions might be useful for amplification near the quantum limit, being powered by simple DC voltage and providing a different trade-off between gain, bandwidth and dynamic range, which could be advantageous in some situations.