LAUSR

Abstract A DNA molecule formed by a cytosine-guanine sequence ((CG)n) exhibits a conformational transition from the B-form to the Z-form by varying the ionic environment. This study reports coherent spin transport in a molecule of double strand 5′-(CG)n-3′ (n = 2, 3, 4) under a magnetic proximity effect from ferromagnetic nickel electrodes. The calculation was performed by using a Landauer-Buttiker formula based on a non-equilibrium Green’s function with density functional theory. The conformational transition led to about a 10 times change in conductance, which is similar to the experimental results. In addition, the absolute value of the tunnel magnetoresistance ratio had a tendency to decrease with the conformational transition. The calculation result suggests that not only a change in conductance but also a change in the magnetoresistance ratio can be used to monitor the conformation of a DNA molecule sensitively.