Charge Transport in a Multiterminal DNA Tetrahedron: Interplay among Contact Position, Disorder, and Base-Pair Mismatch

As a secondary structure of DNA, DNA tetrahedra exhibit intriguing charge transport phenomena and provide promising platform for wide applications like biosensors, as shown in recent electrochemical experiments. Here, we study multi-terminal tetrahedron, finding that its properties strongly depend upon the interplay among contact position, on-site energy disorder, base-pair mismatch. Our results indicate efficiency is nearly independent position weak disorder regime, dramatically declined by occurrence single mismatch between source drain, accordance with experimental [J. Am. Chem. Soc. {\bf 134}, 13148 (2012); Sci. 9}, 979 (2018)]. By contrast, could be enhanced monotonically shifting toward drain strong increased when takes place exactly at position. In particular, moves successively from top vertex to through tetrahedral device can separated into three regimes, ranging disorder-induced linear decrement disorder-insensitive transport, disorder-enhanced transport. Finally, predict tetrahedron functions more efficient spin filter compared double-stranded opposite polarization observed different drains, which may used separate spin-unpolarized electrons spin-up ones spin-down ones. These readily checked measurements help designing novel tetrahedron-based molecular nanodevices.