Probing the strongly driven spin-boson model in a superconducting quantum circuit

  1. L. Magazzù,
  2. P. Forn-Díaz,
  3. R. Belyansky,
  4. J.-L. Orgiazzi,
  5. M. A. Yurtalan,
  6. M. R. Otto,
  7. A. Lupascu,
  8. C. M. Wilson,
  9. and M. Grifoni
Quantum two-level systems interacting with the surroundings are ubiquitous in nature. The interaction suppresses quantum coherence and forces the system towards a steady state. Such
dissipative processes are captured by the paradigmatic spin-boson model, describing a two-state particle, the „spin“, interacting with an environment formed by harmonic oscillators. A fundamental question to date is to what extent intense coherent driving impacts a strongly dissipative system. Here we investigate experimentally and theoretically a superconducting qubit strongly coupled to an electromagnetic environment and subjected to a coherent drive. This setup realizes the driven Ohmic spin-boson model. We show that the drive reinforces environmental suppression of quantum coherence, and that a coherent-to-incoherent transition can be achieved by tuning the drive amplitude. An out-of-equilibrium detailed balance relation is demonstrated. These results advance fundamental understanding of open quantum systems and bear potential for applications in quantum technologies.