Magnetic-field and tunable-barrier effects on charge transport in DNA heterostructures

The tunable barrier and magnetic field effects are studied in the electron transport of the double-stranded DNA molecular electronic structure. Our theoretical approach involves the application of the two-dimensional tight-binding Schrödinger equation to calculate transmission and electric current through the nearest-neighbors of twenty base-pairs’ DNA. A combination of G-C and A-T base-pairs of DNA, which can be considered as a barrier and a well, forms a superlattice in semiconductor heterostructures and exhibits a miniband whose width depends on the strength of the barriers and energy level of the wells. We also incorporate a variation of magnetic field flux density into the hopping integrals as a phase factor and observe Aharonov-Bohm (AB) oscillations in the transmission. It is shown that for non-zero magnetic flux, the transmission zero leaves the real-energy axis and moves up into the complex-energy plane. We also point out that both the hydrogen bonds between the base pair and the coupling between leads and DNA with flux variations play a role to determine the periodicity of AB oscillations in the transmission.