A spin modulating device, tuned by the Fermi energy, in honeycomb-like substrates periodically stubbed with transition-metal-dichalkogenides

Abstract

We investigate spin transport through graphene-like substrates stubbed vertically with transition-metal-dichalkogenides (TMDs). A tight-binding model is used based on a graphene-like Hamiltonian that includes different types of spin-orbit coupling (SOC) terms permitted by the C3v symmetry group in TMDs/graphene-like heterostructures. The results show a spin modulation obtained by tuning the strength and sign of the Fermi energy EF and not by varying the SOC strength as is mainly the case of Datta and Das. The spin conductance is directly controlled by the value of EF . In addition, a perfect electron-spin modulation is obtained when a vertical strain is introduced. In this case, the spin conductance exhibits a strong energy dependence. The results may open the route to a combination of graphene-like substrates with TMD stubs and the development of spin-transistor devices controlled by the Fermi energy rather than the SOC strength.

Spin-dependent polarization and quantum Hall conductivity in decorated graphene: influence of locally induced spin–orbit-couplings and impurities

“…Motivated by the development of spin injection and detection in 2D based materials [49,50] and by the energy-dependent spin polarization that has been shown in our recent work of TMDs/graphene-like heterostructure [46]. We undertake a systematic analysis of the role of the locally induced SOC contributions separately.…”

“…Additionally, the sign of λ PIA and the ratio λ PIA / λ I influence in a major way the spin-up and spin-down transmission of the outgoing electrons within the first propagating mode. In fact, the case which describes the general couplings belongs to the point group C 3v symmetry and might be considered if the strips contain group impurities of TMDCs as was discussed in our previous work [46].…”

“…Accordingly, new devices able to provide a strong energy dependence of the spin conductance would be highly desirable. We that in mind, we have previously investigated an alternative device able to tune the spin polarization by varying E F [46] and that transition-metal dichalkogenides on graphene-like heterostructures can work as spin switching devices tuned by E F . This is easier than achieving an energydependent modulation with a strong RSOC.…”

Transverse currents in spin transistors

“…SOC can be induced in graphene by proximitizing it with transition metal dichalcogenides [40,41]. Inducing ferromagnetism in graphene has also been discussed in literature [42,43].…”

“…Inducing ferromagnetism in graphene has also been discussed in literature [42,43]. While the strength of SOC in Datta-Das transistor is varied to control the conductance, gate voltage can be used to control the conductances in graphene heterostructures [40]. It will be an interesting future direction to explore transport in spin transistors designed on graphene due to its high electron mobility and the Dirac nature.…”