Results for transmission through the $\mathrm{poly}\{G\}$ DNA molecule are presented. We show that (i) periodically arranged sodium counterions in close proximity to dry DNA give rise to a conduction channel, and aperiodicity in the counterion sequence can lead to a significant reduction in conduction, (ii) modification of the rise of B-DNA induces a change in the width of the transmission window, and (iii) specifically designed sequences are predicted to show intrinsic resonant tunneling behavior.

• Received 29 January 2002

DOI:https://doi.org/10.1103/PhysRevB.67.081405