Bang-bang decoupling used in quantum optics for the first time
Sajeev Damodarakurup · SPIE Newsroom · 2009
Experimental suppression of polarization decoherence in a ring cavity uses a simple open-loop control technique known as bang-bang decou-pling. In recent years new strategies for maintaining the coherence (i.e., constant relative phase) of quantum systems have appeared.1, 2 Even if photons interact weakly with their surroundings, the re-sulting decoherence (i.e., randomization of the relative phase) may significantly affect their polarization state during propaga-tion within dispersive media. We show how the polarization de-coherence of a photon circling in a ring cavity can be suppressed by adapting to the field of quantum optics the open-loop pro-tection technique known as bang-bang (BB). This method is al-ready being employed for nuclear spins and nuclear-quadrupole qubits. It has potential practical application in the field of optical fibers.