Giant valley-polarized spin splittings in magnetized Janus Pt dichalcogenides

We reveal giant proximity-induced magnetism and valley-polarization effects in Janus Pt dichalcogenides (such as SPtSe), when bound to the Europium oxide (EuO) substrate. Using first-principles simulations, it is surprisingly found that charge redistribution, resulting from proximity with EuO, leads formation of two K K$^{'}$valleys conduction bands. Each these valleys displays its own spin polarization a specific spin-texture dictated by broken inversion time-reversal symmetries, valley-exchange Rashba splittings large hundreds meV. This provides platform for exploring novel spin-valley physics low-dimensional semiconductors, potential transport mechanisms such spin-orbit torques much more resilient disorder temperature effects.