Scanning tunneling potentiometry implemented into a multi-tip setup by software

TL;DR

This paper introduces a software-implemented multi-tip scanning tunneling potentiometry method that enables high-resolution local electric potential measurements and transport mapping without hardware modifications.

Contribution

It presents a novel software-based approach to integrate potentiometry into existing multi-tip STM setups, allowing in situ contact, topography, and potential measurements at atomic scales.

Findings

Achieved a resolution in electric potential measurements.

Demonstrated local transport field mapping on semiconductor surfaces.

Validated the technique with thermovoltage measurements and standing wave resolution.

Abstract

We present a multi-tip scanning tunneling potentiometry technique that can be implemented into existing multi-tip scanning tunneling microscopes without hardware changes. The resulting setup allows flexible in situ contacting of samples under UHV conditions and subsequent measurement of the sample topography and local electric potential with resolution down to \AA\ and \mu V, respectively. The performance of the potentiometry feedback is demonstrated by thermovoltage measurements on the Ag/Si$(111)-(\sqrt3\times\sqrt3)\rm R30^{\circ}$ surface by resolving a standing wave pattern. Subsequently, the ability to map the local transport field as a result of a lateral current through the sample surface is shown on Ag/Si$(111)-(\sqrt3\times\sqrt3)\rm R30^{\circ}$ and Si$(111)-(7\times7)$ surfaces.