First Principle Study of Temperature-Dependent Magnetoresistance and Spin Filtration Effect in WS₂ Nanoribbon

Abstract

An applicable use of density functional theory (DFT) along with nonequilibrium Green's function (NEGF) is done for exploring the temperaturedependent spin electron transport nature in a ferromagnetic tungsten disulfide (WS 2 ) nanoribbon. To demonstrate the effect of temperature on spin filtration and spin Seebeck effect, we evaluated vital parameters such as spin-polarized current and spin filtration efficiency. Spin filtration efficiency of around ∼95% is obtained in the high-temperature difference range. The high temperature (T L ) of the left electrode in comparison to the high temperature (T R ) of the right electrode results in higher and lower spin filtration efficiency in parallel magnetization (PM) and antiparallel magnetization (APM), respectively. Transmission spectrum plots at equilibrium are also calculated in PM and APM to justify the temperature-dependent spin transport behavior in the WS 2 nanoribbon. Giant thermal magnetoresistance around 1.934 × 10 3 % is achieved. The temperature-dependent negative differential resistance behavior of the current plot has been observed. Huge value of thermal magnetoresistance (MR) and excellent spin filtration obtained for WS 2 nanoribbon suggests the potential application of this material in spin caloritronic devices.

Tuning the spin caloritronic transport properties of InSe monolayers via transition metal doping

“…For example, when the T L is fixed at 300 K, when the DT changes from 50 to 200 K, the Z just varies very slightly from 99.98% to 99.76%, which are significantly larger than that of the device based on a WS 2 nanoribbon and VSe 2 monolayer. 21,22 (iii) An obvious negative differential thermal resistance (NDTR) appears in the current curves of the spin-down electrons, as shown in Fig. 1(b).…”

“…For example, when the T L is fixed at 300 K, when the Δ T changes from 50 to 200 K, the η just varies very slightly from 99.98% to 99.76%, which are significantly larger than that of the device based on a WS 2 nanoribbon and VSe 2 monolayer. 21,22…”

“…15 In recent years, two-dimension (2D) materials represented by graphene have drawn considerable attention due to their distinctly different properties from the bulk counterparts. 1,[19][20][21][22][23][24] However, the applications of graphene in modern nanodevices are limited due to the absence of an energy gap in the band structure. Among various layered 2D materials, due to the environmental stability (i.e.…”

Theoretical and experimental study on the electronic and optical properties of K0.5Rb0.5Pb2Br5: a promising laser host material

“…Recently, the density functional theory (DFT) has been successfully performed to study many systems including monolayers, nanoribbons, and bulks. [27][28][29][30][31][32] The DFT calculations can be used to not only validate experimental results but also to give insight to the electronic, and optical properties of a semiconductor. 27 In current study, the DFT calculations were performed by applying augmented plane-wave method (APW) 33,34 in the framework of Kohn-Sham equations.…”

Electronic structures of WS2 armchair nanoribbons doped with transition metals

“…DFT calculations have also predicted that WS 2 and MoS 2 nanoribbons can form in-plane heterostructures 23,24 with rectifying and/or spin-filtering functions 24 , rendering them attractive nanoelectronic devices. A theoretical study 25 obtained a very large thermal magnetoresistance value and excellent spin filtration for a WS 2 nanoribbon sandwiched between two electrodes that featured a temperature differential.…”