Modulation of spin transport in DNA-based nanodevices by temperature gradient: A spin caloritronics approach

Spin caloritronics, a novel and rich research field, combining spin, charge and heat transport in materials, provides alternative strategies for thermoelectric waste heat recovery, and the information technologies. Understanding of the spin transport properties of materials has important implications for spin-based devices. Flexibility, low cost, and adjustable conductance are the important factors to consider the spin transport properties of DNA chains. The spin current corresponding to spin-up and spin-down electrons in the presence of a temperature gradient along the DNA chain are calculated. ∇T=1K/Å is the most appropriate temperature gradient in which the maximum spin current flows. The spin current of different sequences determines the best sequence for spin transport in different situations. Applying the external magnetic field can amplify the spin current along the DNA chain, and one can choose the most appropriate field. Is−V characteristic diagrams corresponding to different sequences are distinctive and determine the spin-dependent negative differential resistance (SNDR) regions corresponding to the negative slope intervals. Eventually, the spin-dependent Seebeck effect (SDSE) in DNA and the SDSE coefficients as a function of temperature are studied. The peak of the SDSE diagrams is different for different species of sequences. Poly(AT), hc1, and poly(CG) show maximum peaks of SDSE coefficient at 300, 310, and 320 K, respectively. Therefore, one can design a DNA based spin nanodevice with maximal efficiency in different situations.