Joule-Thompson Scanning Tunnelling Microscope (JT-STM)

The JT-STM is a sophisticated tool dedicated to the study of the electronic and magnetic properties of functional magnetic nanostructures, e.g. magnetic molecules, under ultrahigh vacuum conditions (UHV) and at low temperatures, which are thought to serve as essential building blocks for spintronic devices.

JT-STM Head.jpg

The main instrumental features are the low operating temperature, the long holding times, and a magnetic field in the vertical direction. The instrument utilizes the Joule-Thompson effect of 4He and reaches a minimum temperature of about 1.1 K. Its low Helium consumption enables continuous measurements at low temperatures for more than four days.

A superconducting split coil magnet is mounted inside the UHV and generates magnetic fields of up to 3 T perpendicular to the sample surface. The extremely stable design leads to low drift rates (170 and 50 pm/h for the lateral and vertical direction, respectively).  The z-noise of the STM tip is extremely low (1.4 and <1 pm rms in 0.4 – 40 Hz and 1 – 300 Hz range, respectively). Thus, the instrument allows extended time periods of measurements with the tip positioned on top of atomic-sized sample features.

The figure above shows the JT-STM head without cooling shields.

Dr. Frank Matthes
Dr. Daniel E. Bürgler

Sketch .jpg
Figure: 3D model of the JT-STM
JT Set Up.jpg
Experimental set-up of the Joule-Thompson STM system.

Results

1. Quantum interference effects in molecular spin hybrid

2. Spin-Hybrids: A Single-Molecule Approach to Spintronics

Letzte Änderung: 23.03.2022