Inhibition of decoherence in flying qubits
Sajeev Damodarakurup, Marco Lucamarini, Giovanni Di Giuseppe, David Vitali, P. Tombesi · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2009
In recent years the interest in the manipulation of quantum systems has furthered new strategies for maintaining their coherence, continuously threatened by unwanted and uncontrollable interactions with the environment. Photons interact weakly with the surroundings. Even so decoherence may significantly affect their polarization state during the propagation within dispersive media because of the unavoidable presence of more than a single frequency in the envelope of the photon pulse. Here we report on a suppression of the polarization decoherence in a ring cavity obtained by properly retooling for the photon qubit the "bang-bang" protection technique already employed for nuclear spins and nuclear-quadrupole qubits. Our results show that bang-bang control can be profitably extended to all quantum information processes involving flying polarization qubits.