Millisecond spin-flip times of donor-bound electrons in GaAs

We observe millisecond spin-flip relaxation times of donor-bound electrons in high-purity n-GaAs. This is three orders of magnitude larger than previously reported lifetimes in n-GaAs. Spin-flip times are measured as a function of magnetic field and exhibit a strong power-law dependence for fields greater than 4 T. This result is in qualitative agreement with previously reported theory and measurements of electrons in quantum dots.