A subKelvin scanning probe microscope for the electronic spectroscopy of an individual nano-device

TL;DR

This paper introduces a cryogenic scanning probe microscope capable of high-precision electronic spectroscopy on individual nano-devices at sub-Kelvin temperatures, combining atomic force and tunneling microscopy techniques.

Contribution

It presents a novel integrated microscope design optimized for low-temperature electronic spectroscopy of nano-devices, including precise alignment and local tunneling measurements.

Findings

Successful local tunneling spectroscopy of a hybrid Josephson junction.

Effective cryogenic alignment using tuning fork resonator probes.

Maintained low heating during sample displacement.

Abstract

We present a combined scanning force and tunneling microscope working in a dilution refrigerator that is optimized for the study of individual electronic nano-devices. This apparatus is equipped with commercial piezo-electric positioners enabling the displacement of a sample below the probe over several hundred microns at very low temperature, without excessive heating. Atomic force microscopy based on a tuning fork resonator probe is used for cryogenic precise alignment of the tip with an individual device. We demonstrate the local tunneling spectroscopy of a hybrid Josephson junction as a function of its current bias.