Fig. 4: Amplification by the SL periodicity.
From: Topologically protected spin diffusion and spin generator using chalcogenide superlattices
a Relationship between the number of Ge2Te2 unit layers and VISH again, using Device-C (blue), where jc and electrode distance were fixed to 2 mA and 200 μm, respectively. VISHs of a 6.0 nm-thick Sb2Te3 layer (green diamond) and of a 4.8 nm-thick GeTe layer (red square) corresponding to the total thickness of the SL with n = 6 are shown together. Inset: a schematic of the SL stacking structures. b A cross-sectional view of a six-periodic SL composed of the (Ge2Te2)/(Sb2Te3) bilayers using a transmission electron microscope (TEM). At every five (Sb2Te3), seven (Sb2Te3 + GeTe), and nine (Sb2Te3 + GeTeGeTe) atoms, a vdW gap are inserted to get the energy minimum.
