A 350 mK, 9 T scanning tunneling microscope for the study of superconducting thin films and single crystals

TL;DR

This paper presents a low temperature, high magnetic field scanning tunneling microscope capable of atomic resolution and spectroscopic measurements on superconducting thin films and crystals, with innovative design features.

Contribution

The paper introduces a novel STM design that operates at 350mK and 9T, with in-situ sample preparation capabilities for superconducting materials.

Findings

Atomic resolution imaging of NbSe2

Spectroscopic mapping of disordered NbN thin film

Successful operation at 350mK and 9T magnetic field

Abstract

We report the construction and performance of a low temperature, high field scanning tunneling microscope (STM) operating down to 350mK and in magnetic fields up to 9T, with thin film deposition and in-situ cleaving capabilities. The main focus lies on the simple design of STM head allowing top loading of the sample and innovative sample holder design that allows us to get spectroscopic data on superconducting thin films grown in-situ on insulating substrates. Other design details on sample transport, chamber and vibration isolation scheme are also described. We demonstrate the capability of our instrument through the atomic resolution imaging and spectroscopy on NbSe2 single crystal and spectroscopic maps obtained on homogeneously disordered NbN thin film.