Spin-dependent Seebeck Effect, Thermal Colossal Magnetoresistance and Negative Differential Thermoelectric Resistance in Zigzag Silicene Nanoribbon Heterojunciton

Abstract

Spin-dependent Seebeck effect (SDSE) is one of hot topics in spin caloritronics, which examine the relationships between spin and heat transport in materials. Meanwhile, it is still a huge challenge to obtain thermally induced spin current nearly without thermal electron current. Here, we construct a hydrogen-terminated zigzag silicene nanoribbon heterojunction, and find that by applying a temperature difference between the source and the drain, spin-up and spin-down currents are generated and flow in opposite directions with nearly equal magnitudes, indicating that the thermal spin current dominates the carrier transport while the thermal electron current is much suppressed. By modulating the temperature, a pure thermal spin current can be achieved. Moreover, a thermoelectric rectifier and a negative differential thermoelectric resistance can be obtained in the thermal electron current. Through the analysis of the spin-dependent transport characteristics, a phase diagram containing various spin caloritronic phenomena is provided. In addition, a thermal magnetoresistance, which can reach infinity, is also obtained. Our results put forward an effective route to obtain a spin caloritronic material which can be applied in future low-power-consumption technology.

Spin Seebeck effect and thermoelectric phenomena in superconducting hybrids with magnetic textures or spin-orbit coupling

“… 25 , but here extended from collinear magnetic alignment and including a computation of the spin Seebeck effect. The thermal generation of a spin current and an associated spin voltage is known as the spin 47 or spin-dependent 48 Seebeck effect (we will stick with the former notation in this manuscript). Within the quasiclassical approximation, only particles with energies close to the Fermi surface are assumed to contribute to transport, and the Green function matrices are nearly isotropic with respect to momentum 49 .…”

Magnetic properties of silicene nanoribbons: A DFT study

“…Dirac-like electron dispersion, 14,15 extremely high carrier mobility, 16 spin Hall effect, 17 and spin Seebeck effect, 18 but also some superior features, such as large spin filter effect. 19 large spin-orbital coupling, 22 which is important for achieving topological insulating states.…”

Nanoribbons: From fundamentals to state-of-the-art applications

“…It was found that increasing the width of armchair applying temperature difference between source and drain results in oppositely flowing spin-up and spin-down currents indicating thermal spin currents in zigzag SiNRs. 109 Creating opposite spin currents reduces the conducting electron current in the material and thus, the related Joule heating is much suppressed which indicates potential applications of zigzag SiNRs in low-power-consumption technology. An et al studied spin-polarized currents in SiNRs by applying local exchange field and reported that upon applying a weak local exchange field parallel to the surface of SiNRs on one of the edges of the NR, a gap is induced in the corresponding edge states while another pair of gapless edge states with opposite spin are still protected by time-reversal symmetry.…”