Thermoelectric transport in poly(G)-poly(C) double chains

Electronic and phononic transport in DNA systems with macroscopic length are studied by means of a real-space renormalization method within the Boltzmann formalism, where the poly(G)-poly(C) base-pair segments arranged following periodic and Fibonacci sequences are comparatively analyzed. The fishbone model and the two-site coarse grain model based on the Born potential including central and non-central interactions are respectively used for the calculation of electrical and lattice thermal conductivities of these DNA systems connected to two reservoirs at their ends. The results show the appearance of gaps in phononic transmittance spectra of segmented poly(G)-poly(C) double chains, which leads to a better thermoelectric figure of merit (ZT) than that of corresponding non-segmented systems. Such ZT can be further improved by introducing a long-range quasiperiodic order, which avoids the thermal transport of numerous low-frequency phonons responsible of the lattice thermal conduction at low temperature. Finally, the influence of reservoirs on ZT is also investigated.