This STM is our oldest setup and has served for many years. It will be retired, soon and will be reborn as a 100 mK dilution incarnation. Currently, it is used for ESR/FMR STM with frequencies up to 13 GHz
This STM is our workhorse for molecular electronics studies including molecular memories, switches and motors.
1K photon STM
The STM was developed by Kevin Edelman in our group in collaboration with the group of Prof. Wegener and combines low temperature STM with the collection of photons emitted from the tunneling junction. For this, special microscopic mirror tips were fabricated using 3d lithography. They focus almost all of the emitted light from the tunneling junction to an optical fiber that guides the light from the cryostat to the external CCD spectrometer or photon correlator.
Design of a photon collecting STM operating at 1 K. The microscopic tip is manufactured using 3d lithography and focuses the light from the tunneling junction by use of a parabolic mirror into an optical fiber (see: Light collection from a low-temperature scanning tunneling microscope using integrated mirror tips fabricated by direct laser writing, K. Edelmann, L. Gerhard, M. Winkler, L. Wilmes, V. Rai, M. Schumann, C. Kern, M. Meyer, M. Wegener, W. Wulfhekel, Review of Scientific Instruments 89, 123107 (2018))
680 mK STM
The STM is our workhorse for studies of magnetism and superconductivity. It combines a dry magnet with up to 3T magnetic field with closed cycle Joule-Thomson cooling using 3He gas. The cryostat and the STM was developed by Lei Zhang in our group. It has extremely low He consumption of only 30 ml of He per hour allowing for standing times of up to 280 hours with one filling.
Design sketch of our JT-STM with ultra low He consumption (see: A compact sub-Kelvin ultrahigh vacuum scanning tunneling microscope with high energy resolution and high stability, L. Zhang, T. Miyxamachi, T. Tomanic, R. Dehm, W. Wulfhekel, Review of Scientific Instruments 82, 103702 (2011))
25 mK STM
Our dilution STM is the most extreme instrument in our group going down to a thermodynamic temperature of 25 mK and an electronic temperature below 60 mK. It allows fields of >6 T and has extremely short turnaround times. In just an hour, you can bring a new sample to base temperature. It was developed by Timofey Balashov in our group.
Sketch of our compact 25 mK STM (see: A compact ultrahigh vacuum scanning tunneling microscope with dilution refrigeration,T. Balashov, M. Meyer, W. Wulfhekel, Review of Scientific Instruments 89, 113707 (2018))
We have licensed our technology to some of the world leading companies for UHV cryogenic applications including Cryovac GmbH & Co KG, SPECS Surface Nano Analysis GmbH, Unisoku Co. Ltd. and Suzhou Hengwei Instruments Technology Co. Ltd. Our know-how can be found in many laboratories and universities around the globe.