I. Fuentes

Generating Multimode Entangled Microwaves with a Superconducting Parametric Cavity

  1. C.W. Sandbo Chang,
  2. M. Simoen,
  3. José Aumentado,
  4. Carlos Sabín,
  5. P. Forn-Díaz,
  6. A. M. Vadiraj,
  7. Fernando Quijandría,
  8. G. Johansson,
  9. I. Fuentes,
  10. and C.M. Wilson
In this Letter, we demonstrate the generation of multimode entangled states of propagating microwaves. The entangled states are generated by parametrically pumping a multimode superconducting
cavity. By combining different pump frequencies, applied simultaneously to the device, we can produce different entanglement structures in a programable fashion. The Gaussian output states are fully characterized by measuring the full covariance matrices of the modes. The covariance matrices are absolutely calibrated using an in situ microwave calibration source, a shot noise tunnel junction. Applying a variety of entanglement measures, we demonstrate both full inseparability and genuine tripartite entanglement of the states. Our method is easily extensible to more modes.
arxiv pdf

Relativistic Motion with Superconducting Qubits

  1. S. Felicetti,
  2. C. Sabín,
  3. I. Fuentes,
  4. L. Lamata,
  5. G. Romero,
  6. and E. Solano
We show how the dynamical modulation of the qubit-field coupling strength in a circuit quantum electrodynamics architecture mimics the motion of the qubit at relativistic speeds. This
allows us to propose a realistic experiment to detect microwave photons coming from simulated acceleration radiation. Moreover, by combining this technique with the dynamical Casimir physics, we enhance the toolbox for studying relativistic phenomena in quantum field theory with superconducting circuits.
arxiv pdf