Aziza Suleymanzade

A tunable High-Q millimeter wave cavity for hybrid circuit and cavity QED experiments

  1. Aziza Suleymanzade,
  2. Alexander Anferov,
  3. Mark Stone,
  4. Ravi K. Naik,
  5. Jonathan Simon,
  6. and David Schuster
The millimeter wave (mm-wave) frequency band provides exciting prospects for quantum science and devices, since many high-fidelity quantum emitters, including Rydberg atoms, molecules
and silicon vacancies, exhibit resonances near 100 GHz. High-Q resonators at these frequencies would give access to strong interactions between emitters and single photons, leading to rich and unexplored quantum phenomena at temperatures above 1K. We report a 3D mm-wave cavity with a measured single-photon internal quality factor of 3×107 and mode volume of 0.14×λ3 at 98.2 GHz, sufficient to reach strong coupling in a Rydberg cavity QED system. An in-situ piezo tunability of 18 MHz facilitates coupling to specific atomic transitions. Our unique, seamless and optically accessible resonator design is enabled by the realization that intersections of 3D waveguides support tightly confined bound states below the waveguide cutoff frequency. Harnessing the features of our cavity design, we realize a hybrid mm-wave and optical cavity, designed for interconversion and entanglement of mm-wave and optical photons using Rydberg atoms.
arxiv pdf

Millimeter-Wave Four-Wave Mixing via Kinetic Inductance for Quantum Devices

  1. Alexander Anferov,
  2. Aziza Suleymanzade,
  3. Andrew Oriani,
  4. Jonathan Simon,
  5. and David I. Schuster
Millimeter-wave superconducting devices offer a platform for quantum experiments at temperatures above 1 K, and new avenues for studying light-matter interactions in the strong coupling
regime. Using the intrinsic nonlinearity associated with kinetic inductance of thin film materials, we realize four-wave mixing at millimeter-wave frequencies, demonstrating a key component for superconducting quantum systems. We report on the performance of niobium nitride resonators around 100 GHz, patterned on thin (20-50 nm) films grown by atomic layer deposition, with sheet inductances up to 212 pH/square and critical temperatures up to 13.9 K. For films thicker than 20 nm, we measure quality factors from 1-6×104, likely limited by two-level systems. Finally we measure degenerate parametric conversion for a 95 GHz device with a forward efficiency up to +16 dB, paving the way for the development of nonlinear quantum devices at millimeter-wave frequencies.
arxiv pdf