Frequency-independent voltage amplitude across a tunnel junction

TL;DR

This paper introduces a new calibration method to achieve a frequency-independent rf voltage amplitude across a tunnel junction, enhancing the capabilities of rf scanning tunneling microscopy for advanced applications.

Contribution

The paper presents an alternative calibration technique that ensures consistent rf voltage amplitude across frequencies, improving upon previous methods.

Findings

The new calibration method successfully achieves frequency-independent rf voltage.

The procedure is applicable to various devices delivering rf to tunnel junctions.

Experimental results demonstrate improved rf amplitude stability.

Abstract

Radio-frequency (rf) scanning tunneling microscopy has recently been advanced to methods such as single-atom spin resonance. Such methods benefit from a frequency-independent rf voltage amplitude across the tunnel junction, which is challenging to achieve due to the strong frequency dependence of the rf attenuation in a transmission line. Two calibration methods for the rf amplitude have been reported to date. In this Note, we present an alternative method to achieve a frequency-independent rf voltage amplitude across the tunnel junction and show the results of this calibration. The presented procedure is applicable to devices that can deliver rf voltage to a tunnel junction.