Universal phase shift and nonexponential decay of driven single-spin oscillations

Phys Rev Lett. 2007 Sep 7;99(10):106803. doi: 10.1103/PhysRevLett.99.106803. Epub 2007 Sep 7.


We study, both theoretically and experimentally, driven Rabi oscillations of a single electron spin coupled to a nuclear-spin bath. Because of the long correlation time of the bath, two unusual features are observed in the oscillations. The decay follows a power law, and the oscillations are shifted in phase by a universal value of approximately pi/4. These properties are well understood from a theoretical expression that we derive here in the static limit for the nuclear bath. This improved understanding of the coupled electron-nuclear system is important for future experiments using the electron spin as a qubit.