Andreev reflection and subgap conductance in monolayer MoS2 ferromagnet/s and d-wave superconductor junction

• Andreev reflection and resulting subgap conductance in a $MoS_2$-based ferromagnetic superconductor are investigated.
• The accurate form of electron-hole excitations and corresponding Dirac-like spinors are exactly obtained.
• we consider the difference of superconducting gap under electron-hole converting, taking place in the $d$-wave order.
• Strong spin-splitting occurs in valence band of nondegenerate $K$ and $K′$ valleys due to exchange field.
• Exchange energy causes a distinct behavior in Andreev process between spin-up and spin-down charge carriers.

The accurate and proper form of electron-hole excitations and corresponding Dirac-like spinors of superconducting monolayer molybdenum disulfide are exactly obtained. Andreev reflection and resulting subgap conductance in a MoS2-based ferromagnet-superconductor (F/S) junction are particularly calculated in terms of dynamical characteristics of structure. Due to the spin-splitting energy gap in the valence band and also nondegenerate K and K′ valleys, the ferromagnetic exchange energy sh can cause a distinct behavior of Andreev reflection process between spin-up and spin-down charge carriers in the different valleys. In order to occur the retro Andreev reflection, the chemical potential is necessarily fixed in a determined range. Given here one-particle superconducting bispinors enable us to explicitly involve the anisotropic superconducting gap ΔS under electron-hole conversion, i.e., taking place in d-wave asymmetry. Dependence of the Andreev process on the electron incidence angle at the interface is explicitly explored in the presence of such superconducting pair potential.