Observation of the inverse spin Hall effect in the topological crystalline insulator SnTe using spin pumping

Abstract

Topological crystalline insulator SnTe is a promising material for future spintronics applications because of the strong spin-orbit coupling and surface states protected by the mirror symmetry of the crystal. In this paper, using a high-quality epitaxial ( 001)-oriented Fe/SnTe/CdTe/ZnTe heterostructure grown on GaAs, we successfully observe the inverse spin Hall effect in SnTe induced by spin pumping, which is confirmed by detailed analyses of the dependence of the electromotive force on the microwave power, magnetic-field angle, and temperature. By a rough estimation, a relatively large spin Hall angle of ∼0.01 is obtained for bulk SnTe at room temperature. This large value may be partially caused by the surface states. Our result suggests that SnTe can be used for efficient spin-charge current conversion.

Spin Hall effect in prototype Rashba ferroelectrics GeTe and SnTe

“…However, the polar distortions of SnTe are suppressed already at 0.02|e|/u.c., thus the giant spin Hall effect should rather be attributed to the paraelectric phase. In fact, the estimated spin Hall angle is in good agreement with the experimental value of 0.01 measured in the high-temperature rocksalt structure by Ohya et al 24 Although it has been suggested that the topological surface states could enhance the efficiency of spin Hall effect, our analysis shows that the large spin Hall angle can be entirely assigned to the strong SOC of bulk electronic states in the cubic structure. Thus, despite the realization of FERSC seem difficult in this material, it is extremely promising for spintronics applications based on spin Hall effect.…”

“…23 Finally, recent spin pumping experiments performed for the high-symmetry paraelectric bulk revealed strong spin Hall effect whose origin remains elusive. 24 Our calculations based on density functional theory (DFT) allowed us to quantitatively estimate spin Hall conductivities (SHC) for low-and high-symmetry structures of both materials. First, we have unveiled that the ferroelectric phase could indeed enhance the spin Hall effect as compared with the paraelectric structure.…”

Giant spin-to-charge conversion at an all-epitaxial single-crystal-oxide Rashba interface with a strongly correlated metal interlayer

“…2a ). Here, ρ is the resistivity of LSMO and n is 1–2 33 . Therefore, the influence of the galvanomagnetic effects is negligibly small.…”

Giant spin Hall effect in two-dimensional monochalcogenides

“…Finally, SHE has been achieved in bulk β−SnTe which suggests that its successful realization in 2D phase is very probable. 45 Despite the values of doping/strain required to reach/tune the giant SHC might seem large, the actual 2D character of these compounds can greatly help to overcome these difficulties. For example, different stacking order or thickness of the multilayer might reduce the required doping or the Fermi level could be additionally shifted by any charge originating from a substrate, 46 or any additional strain could result from lattice constant matching at the interface.…”