Local and reversible change of the reconstruction on Ge(001) surface between c(4 x 2) and p(2 x 2) by scanning tunneling microscopy

The reconstruction on a Ge(001) surface is locally and reversibly changed between c(4 x 2) and p(2 x 2) by controlling the bias voltage of a scanning tunneling microscope (STM) at 80 K. It is c(4 x 2) with the sample bias voltage V-b less than or equal to -0.7 V. This structure can be maintained with V-b less than or equal to 0.6 V. When V-b is higher than 0.8 V during the scanning, the structure changes to p(2 x 2). This structure is then maintained with V-b greater than or equal to -0.6 V. The observed local change of the reconstruction with hysteresis is attributed to the energy transfer process from the tunneling electron to the Ge lattice in the electric field under the STM tip.