Direct evidence for the STM observation of CuO2 plane in Bi2Sr2CaCu2O8 + x and possibility of new tunnel transistor operation

Single crystals of Bi2Sr2CaCu2O8 + x (B12212) were cleaved in air and the resultant cleavage plane, i.e. BiO plane was observed with an ultrahigh vacuum scanning tunneling microscope (UHV-STM) at room temperature. Missing atom rows were found to be introduced deliberately along the ridges of the modulated BiO plane by increasing the cleaving rate. Noting that the missing atom row is a feature marked on the BiO plane, first direct evidence was obtained for the STM observation of the CuO2 plane where the magnitude of the sample bias voltage was reduced less than 0.1 eV. Based on this observation, we shall propose a new type of atom scale tunnel transistor.