Fibonacci-engineered spin and charge thermoelectrics in a long range Su–Schrieffer–Heeger chain: A pathway to giant figure of merit

Abstract

In this work, we present a novel investigation into the spin-dependent thermoelectric performance of an extended Su–Schrieffer–Heeger (SSH) model, showcasing for the first time, how its intrinsic spin filtration mechanism can be strategically harnessed to function as an efficient spin thermoelectric generator. By introducing a Fibonacci-type aperiodic modulation in the onsite energies, we engineer a deterministic disorder that mimics realistic aperiodic systems and profoundly influences transport characteristics. Furthermore, we incorporate both nearest-neighbor (NN) and next-nearest-neighbor (NNN) hopping amplitudes with tunable cosine dependencies, enabling us to meticulously explore the intricate interplay between these hopping processes and its implications on thermoelectric behavior. Our analysis reveals a remarkable enhancement in the dimensionless thermoelectric figure of merit ZT for both charge and spin transport channels, under carefully optimized conditions. Notably, the spin thermoelectric response exhibits distinct advantages, opening a new frontier in the design of next-generation thermoelectric materials and devices. This qualitative study not only deepens our understanding of aperiodic topological systems but also establishes a foundational framework for exploiting spin-based thermoelectricity in low-dimensional platforms.