Local and Reversible Change of the Reconstruction on Ge(001) Surface between c(4x2) and p(2x2) by Scanning Tunneling Microscopy

TL;DR

This study demonstrates that the Ge(001) surface reconstruction can be locally and reversibly switched between c(4x2) and p(2x2) structures by adjusting the STM bias voltage at 80K, revealing hysteresis behavior.

Contribution

It shows for the first time that surface reconstruction on Ge(001) can be controlled reversibly at the nanoscale using STM bias voltage, highlighting inelastic scattering effects.

Findings

Reconstruction switches between c(4x2) and p(2x2) with bias voltage changes.

Hysteresis observed in the reversible structural change.

Reversible change attributed to inelastic electron scattering.

Abstract

The reconstruction on Ge(001) surface is locally and reversibly changed between c(4x2) and p(2x2) by controlling the bias voltage of a scanning tunneling microscope (STM) at 80K. It is c(4x2) with the sample bias voltage V_b =< -0.7V. This structure can be kept with V_b =< 0.6V. When V_b is higher than 0.8V during the scanning, the structure changes to p(2x2). This structure is then maintained with V_b >= - 0.6V. The observed local change of the reconstruction with hysteresis is ascribed to inelastic scattering during the electron tunneling in the electric field under the STM-tip.