Magnetic Field Effects on Nicked DNA Nanostructures

We investigate the impact of magnetic fields on the current-voltage (I-V) properties of structurally modified double-helix DNA nanostructures. Our theoretical approach involves applying the two-dimensional tight-binding Schrödinger equation and the Landauer-Büttiker formalism, incorporating a variation of magnetic flux density into the hopping integrals as a phase factor, to calculate the transmission and electric current through the nearest neighbors of a DNA structure with twenty-five base pairs. The semiconducting behavior of DNA is examined by introducing nicks (small breaks in the DNA backbone) and observing changes in the I-V characteristics as the number of nicks varies. For nicked DNA structures, a magnetic flux penetrating the center of the DNA induces an Aharonov-Bohm (AB) phase difference, producing AB oscillations in the transmission due to quantum interference effects. Finally, we show that the periodicity of the AB oscillations depends on the variation in the number of nicks for a given coupling constant.