In this lecture, we will explore the physics of Bjerrum pairing and its various consequences for non-equilibrium ion transport and the development of neuromorphic functionalities.
Under the effect of electrostatic interaction, ions of opposite signs can form pairs, known as Bjerrum pairs. The physics of this pairing is extremely rich. The formation and nature of Bjerrum pairs depend crucially on dimension and confinement. The two-dimensional case is very special from this point of view, as the nature of the electrostatic interactions induces a Kosterlitz-Thouless-type insulator-conductor transition. Pairing then has drastic consequences for non-equilibrium transport under the action of an electric field : beyond a threshold field, pairs can break and become conductive. This is the Wien phenomenon, first discussed by Onsager in weak electrolytes. In electric field transport through nanopores, this phenomenon induces signatures of the " voltage-gated " type, which have been demonstrated in various experimental systems.
