Coherent Manipulation and Decoherence of S=10 Single-Molecule Magnets

We report coherent manipulation of S=10 Fe-8 single-molecule magnets. The temperature dependence of the spin decoherence time T-2 measured by high-frequency pulsed electron paramagnetic resonance indicates that strong spin decoherence is dominated by Fe-8 spin bath fluctuations. By polarizing the spin bath in Fe-8 single-molecule magnets at magnetic field B=4.6 T and temperature T=1.3 K, spin decoherence is significantly suppressed and extends the spin decoherence time T-2 to as long as 712 ns. A second decoherence source is likely due to fluctuations of the nuclear spin bath. This hints that the spin decoherence time can be further extended via isotopic substitution to smaller nuclear magnetic moments.