Engineering dark states in hybrid quantum systems

Abstract

Hybrid quantum systems combine physical systems with different properties to get the best of both worlds. In our case this means using nitrogen vacancy centers together with superconducting coplanar waveguide resonators. While the resulting system shows promising results, its usage is generally limited by decoherence effects. In this thesis, we want to show a method to improve this by engineering long lived dark states that improve the decay dynamics of our system by a factor 10. This is signifcantly longer than the cavity or the spin decay, enabling our hybrid quantum system to perform better than its individual parts in this regard. We do this by actively shaping our inhomogeneously broadened spin distribution through the insertion of a high power signal at specifc, freely chosen frequencies to excite these spins. The results in this thesis contributed to [S. Putz, A. Angerer, D. O. Krimer, R. Glattauer, William J. Munro, S. Rotter, J. Schmiedmayer and J. Majer. Engineering Long-Lived Dark-States in Electron Spin Ensembles arXiv:1512.00248]. We further test our system under strong driving fields and measure spin echos and bistability.