Coherent proton tunneling in a short hydrogen bonded chain

We suggest a possible mechanism of polarization oscillations of a short hyd rogen bonded chain. This mechanism is given rise to a coherent proton tunne lling along hydrogen bonds and/or around heavy atoms. Such oscillations are similar to the effect of coherent spin tunneling which was observed in sma ll magnetic grains and mesoscopic magnetic molecules. The tunneling frequen cy of these transitions is calculated in the WKB approximation. These tunne l oscillations can be involved into the mechanism of ion transport along a chain without formation and motion of any real defects. The tunneling rate of such a flip-flop process does not depend on temperature. The effect of c oherent tunnel repolarization of a chain can be observed at low temperature s when tunneling processes prevail over thermal activation ones.