Spin echo techniques are essential for achieving long coherence times in solid state quantum memories for light because of inhomogeneous broadening of the spin transitions. Here we study the effects of radio frequency decoherence control pulse imperfections in detail, using both a semi-classical and a fully quantum-mechanical approach. Our results show that high efficiencies and low noise-to-signal ratios can be achieved for the quantum memories in the single-photon regime for realistic levels of control pulse precision. We also analyze errors due to imperfect initial state preparation (optical pumping), showing that they are likely to be more important than control pulse errors in many practical circumstances. These results are crucial for future developments of solid state quantum memories.
© 2011 Optical Society of AmericaPDF Article