Jacutingaite family: An efficient platform for coexistence of spin valley Hall effects, valley spin-valve realization, and layer spin crossover

Jacutingaite family, a family of naturally occurring exfoliable minerals (Pt2HgSe3 and Pd2HgSe3) discovered in Brazil, is recently predicted to be the very first large-gap Kane-Mele quantum spin Hall insulators. However, yet to date, the door is locked for realizing versatile spin-valley based phenomena due to inversion symmetry in this family. By exploiting the inversion symmetry using different strategies such as placing the jacutingaite family in the vertical electric field or growing its composites with some suitable well-matched systems, we reveal several promising valley spin based phenomena in the jacutingaite family. Overall, we achieve the coupled spin valley Hall effect, valley spin-valve effect, Rashba spin splitting around the low-symmetric M point, layer crossover accompanied by spin crossover, and selective-excitation of carriers from opposite valleys in this family. More interestingly, swapping of the induced spin splittings, Berry curvatures, and the spin texture between the two valleys occur upon the reversal of electric field from E-z > 0 to E-z < 0 without destroying the Z(2) topological hallmarks. Meanwhile, considerable hexagonal trigonal warping effects around the K+ and K_ valleys are realized. Furthermore, by applying vertical electric field through interfacial coupling with ferroelectric III2 - VI3 film, valley contrasting Berry curvature in the Pt2HgSe3 layer with a larger spin splitting in the lower conduction band (similar to 188 meV) is achieved in the +P polarization state. By inverting the polarization state from +P to -P, the Fermi level shifts down into the valence band of the Pt2HgSe3 layer (similar to 82 meV) revealing a hole doping in the Pt2HgSe3 layer. This could establish an effective mechanism to control doping levels in the Pt2HgSe3 layer as desirable for achieving superconductivity at finite doping in the jacutingaite family. Our paper provides a path towards integrating valleytronics and spintronics in multivalley materials with broken inversion symmetry.

Automated summary

This study successfully realizes several valley-spin-based phenomena in the Jacutingaite family, such as coupled spin-valley Hall effect, valley spin-valve effect, and spin splitting, by exploiting inversion symmetry using different strategies. It also demonstrates the ability to control doping levels in the Pt2HgSe3 layer through interface coupling, providing a mechanism for achieving superconductivity. Swapping of induced spin splittings and Berry curvatures between the two valleys upon reversal of electric field is observed without destroying the Z(2) topological hallmarks.