High Performance Ultrawide Temperature Range Planar Hall Devices by 2D Hidden‐Rashba Systems

Abstract Lattice symmetry determines the manifestations of the spin‐orbit coupling (SOC) effect in crystals, e.g. spin polarizations in hidden‐spin Rashba systems are concealed by the sublattice inversion symmetry, making spintronic applications impractical with negligible spin lifetimes. Here, high performance planar Hall effect (PHE) devices based on van der Waals 1T‐PtSe 2 thin films with hidden‐Rashba spins are reported. By temperature‐ and layer‐dependent magneto‐transport, the quantum signature of the hidden‐Rashba PHE is unveiled, which exhibits suppressed backscattering for parallelled electric and magnetic fields, and thus, produces an opposite sign to the conventional Rashba‐rooted PHE signals. The inherent strong hidden‐spin SOC allows high performance magnetic device operations from 0.3 K to room temperature (RT), exhibiting an ultralow working heat load of 1 nW below 80 K and retaining a superior RT signal‐to‐noise ratio exceeding 18 000. It is demonstrated that, by eliminating defects and via optimizing device structure, the sensitivity of hidden‐Rashba PHE devices can be efficiently improved to exceed the commercial Hall sensors, making 2D hidden‐spin Rashba systems a promising material platform for spintronics.