Do ions cross angstrom-scale slits as field-dissociated ion pairs?
In plain words
In channels only a few atoms high, the electric attraction between positive and negative ions becomes much stronger because the surrounding water and walls shield it poorly. Theory predicts ions then travel in bound pairs that an applied voltage separates, giving unusual memory-like electrical behavior.
Precise statement
In two-dimensional slits of height $h \sim 0.3$ to 1 nm, reduced dielectric screening raises ion pair binding energies above $k_B T$, and a 2D Wien-type theory predicts that conduction is controlled by field-driven dissociation of Bjerrum pairs, giving nonlinear and hysteretic current-voltage curves with memory times set by pair kinetics. Determine whether measured nonlinear and memristive conductance $G(V, c, h)$ in such slits follows this mechanism quantitatively, as opposed to surface-charge regulation, wall adsorption or dehydration barriers. An answer is a fit-free comparison of predicted and measured $G(V)$ and memory times.
What would settle it
Conductance measurements versus field, salt concentration, valence and slit height in angstrom-scale channels compared with parameter-free predictions of the pair-dissociation theory.
Status in the literature
Predicted in 2021; memristive, synapse-like conductance was reported in 2D nanofluidic channels in 2023 without a unique mechanistic assignment.