J. Bogár

Landau-Zener-Stückelberg-Majorana lasing in circuit QED

  1. P. Neilinger,
  2. S. N. Shevchenko,
  3. J. Bogár,
  4. M. Rehák,
  5. G. Oelsner,
  6. D. S. Karpov,
  7. O. Astafiev,
  8. M. Grajcar,
  9. and E. Il'ichev
We demonstrate amplification (and attenuation) of a probe signal by a driven two-level quantum system in the Landau-Zener regime. In the experiment, a superconducting qubit was strongly
coupled to a microwave cavity, the conventional arrangement of circuit quantum electrodynamics. Two different types of flux qubits show a similar result, lasing at the points where amplification takes place. The experimental data are explained by the interaction of the probe signal with Rabi-like oscillations. The latter are created by constructive interference of Landau-Zener-St\“{u}ckelberg-Majorana (LZSM) transitions during the driving period of the qubit. A detailed description of the occurrence of these oscillations and a comparison of obtained data with both analytic and numerical calculations are given.
arxiv pdf