Baleegh Abdo

Full coherent frequency conversion between two microwave propagating modes

  1. Baleegh Abdo,
  2. Katrina Sliwa,
  3. Flavius Schackert,
  4. Nicolas Bergeal,
  5. Michael Hatridge,
  6. Luigi Frunzio,
  7. A. Douglas Stone,
  8. and Michel H. Devoret
We demonstrate full frequency conversion in the microwave domain using a Josephson three-wave mixing device pumped at the difference between the frequencies of its fundamental eigenmodes.
By measuring the signal output as a function of the intensity and phase of the three input signal, idler and pump tones, we show that the device functions as a controllable three-wave beam-splitter/combiner for propagating microwave modes, in accordance with theory. Losses at the full conversion point are found to be less than 10^-2. Potential applications of the device include quantum information transduction and realization of an ultra-sensitive interferometer with controllable feedback.
arxiv pdf

Non-degenerate, three-wave mixing with the Josephson ring modulator

  1. Baleegh Abdo,
  2. Archana Kamal,
  3. and Michel H. Devoret
The Josephson ring modulator (JRM) is a device, based on Josephson tunnel junctions, capable of performing non-degenerate mixing in the microwave regime without losses. The generic
scattering matrix of the device is calculated by solving coupled quantum Langevin equations. Its form shows that the device can achieve quantum-limited noise performance both as an amplifier and a mixer. Fundamental limitations on simultaneous optimization of performance metrics like gain, bandwidth and dynamic range (including the effect of pump depletion) are discussed. We also present three possible integrations of the JRM as the active medium in a different electromagnetic environment. The resulting circuits, named Josephson parametric converters (JPC), are discussed in detail, and experimental data on their dynamic range are found to be in good agreement with theoretical predictions. We also discuss future prospects and requisite optimization of JPC as a preamplifier for qubit readout applications.
arxiv pdf