Publication Type
Journal
Journal Name
Physical Review Letters
Publication Date
Volume
117
Issue
15
Abstract
Phosphoric acid has one of the highest intrinsic proton conductivities of any known liquids, and the
mechanism of this exceptional conductivity remains a puzzle. Our detailed experimental studies discovered
a strong isotope effect in the conductivity of phosphoric acids caused by (i) a strong isotope shift of the
glass transition temperature and (ii) a significant reduction of the energy barrier by zero-point quantum
fluctuations. These results suggest that the high conductivity in phosphoric acids is caused by a very
efficient proton transfer mechanism, which is strongly assisted by quantum effects.
