NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Maxwell-Hall access resistance in graphene nanopores
Published
Author(s)
Subin Sahu, Michael P. Zwolak
Abstract
The resistance due to the convergence from bulk to a constriction -- e.g., a nanopore -- is a mainstay of transport phenomena. In classical electrical conduction, Maxwell -- and later Hall for ionic conduction -- predicted this access or convergence resistance to be independent of the bulk dimensions and inversely dependent on pore radius, a, for a perfectly circular pore. More generally, though, this resistance is contextual, it depends on the presence of functional groups/charges and fluctuations, as well as the (effective) constriction geometry/dimensions. Addressing the context generically requires all-atom simulations, but this demands enormous resources due to the algebraically decaying nature of convergence. We develop a finite-size scaling analysis -- reminiscent of the treatment of critical phenomena -- that makes the convergence resistance accessible in such simulations. This analysis suggests that there is an ``golden aspect ratio'' for the simulation cell that yields the infinite system result with a finite system. We employ this approach to resolve the experimental and theoretical discrepancies in the radius-dependence of graphene nanopore resistance.
Sahu, S.
and Zwolak, M.
(2018),
Maxwell-Hall access resistance in graphene nanopores, Physical Chemistry Chemical Physics, [online], https://doi.org/10.1039/C7CP07924A
(Accessed October 11, 2025)