Circular DNA shows promise for molecular electronics components
Circular DNA shows promise for molecular electronics components lead image
DNA is the backbone of life and in the future it might be the foundation of our electronics. With high self-assembly and unique conductance properties, DNA has caught the attention of researchers developing molecular electronics. In recent years, researchers have started testing alternative structures to the typical double helix shape, sometimes finding intriguing charge transport phenomena.
To further the study of alternative DNA structures for molecular electronics, Hu et al. conducted a theoretical study of electron transport in circular DNA. Assuming a system where the DNA was connected to two metal electrodes and in a perpendicular magnetic field, the researchers used a model Hamiltonian to simulate electron transport. With the help of the Landauer-Büttiker formula and the Green’s function, the researchers were able to determine the transport properties under different conditions by calculating the conductance, local current and current flowing in the device.
The results showed Aharonov-Bohm-like effects and a Fano resonance that appeared at the DNA’s junction with the electrodes for certain magnetic flux values. They also found the junctions behaved as a nanoscale switch with a large on/off ratio.
“Our results showed Fano resonances can be observed under small magnetic field,” said author Ai-Min Guo. “We hope this will be experimentally confirmed and we are hopeful the critical magnetic field to achieve the switching effect can be reduced.”
The researchers plan to continue studies of electron transport in circular DNA. Specifically they hope to determine the stability of Fano resonances and the switching effect against external environmental factors and to understand spin transport along circular DNA.
Source: “Aharonov-Bohm-like effects and Fano resonances in circular DNA molecular junctions,” by Pei-Jia Hu, Tie-Feng Fang, Ai-Min Guo, and Qing-Feng Sun, Applied Physics Letters (2022). The article can be accessed at https://doi.org/10.1063/5.0118229 .
