# A modular point contact spectroscopy probe for sub-Kelvin applications

## TL;DR

This paper introduces a modular, easy-to-use point contact spectroscopy probe designed for sub-Kelvin environments, enabling efficient sample exchange and versatile low-temperature measurements.

## Contribution

A novel modular probe with a piezo-driven approach mechanism for sub-Kelvin spectroscopy, facilitating quick sample changes without breaking vacuum.

## Key findings

- Successful spectroscopic measurements on elemental superconductors
- Demonstrated functionality with Dirac semimetal PdTe2
- Versatile design adaptable for other transport measurements

## Abstract

We present the construction and performance of a plug-n-play type point contact spectroscopy probe equipped with a piezo-driven coarse approach mechanism for sub-kelvin applications. A modular assembly has been built which can be placed in or taken out from a sub-Kelvin socket mounted inside a He3 cryostat (with a 7 Tesla magnet) using an external manipulator. A simple transfer process using a removable vertical manipulator combined with a load-lock chamber makes the exchange of the sample/tip rig very easy without breaking the vacuum insulation of the sample chamber. We have successfully performed point-contact spectroscopic studies on a few elemental superconductors with low T$_{c}$. We have also used the probe to perform spectroscopic measurements on another low temperature superconductor PdTe$_2$, which is a Dirac semimetal in the normal state. We present such data to demonstrate the functionality of the probe. The probe can also be made adaptable for other transport measurements such as Hall effect, four probe resistivity, scanning tunnelling spectroscopy etc.