Figure 1.

Temperature dependence of (a) resistivity and (b) normalized resistivity at 270 K of Ag_xBi₂Se₃ (x = 0.05 and 0) with various thicknesses. Resistivity is measured in the cooling process. The data from devices of 105 and 60 nm thicknesses were used in our previous report¹⁹. (c) Hysteretic behavior of resistivity observed in Ag_0.05Bi₂Se₃ with 82 nm thickness. Resistivity measured during the cooling and heating processes is indicated by the directions of arrows. (d) Optical microscope image of a sample with 100 nm thickness. Scale bar indicates 10 μm.