Related publications

(1) M. Eltschka, B. Jäck et al., Nano Letters 14, 7171-7174 (2014)
(2) B. Jäck et al., Appl. Phys. Lett. 106, 013109 (2015)
(3) B. Jäck et al., Phys. Rev. B 93, 020504(R) (2016)
(4) B. Jäck, Phys. Rev. Research 2, 043031 (2020)
(5) B. Jäck et al., Nature Physics Reviews 3, 541-554 (2021)
(6) C. Ast et al., Rev. Sci. Instrum. 79, 093704 (2008)

We are convinced that great discoveries are always enabled by technological advancements, which facilitate exploration of otherwise inaccessible phenomena. We previously contributed these advancements by implementing novel measurement methodologies in scanning tunnelling microscopy (STM), such as Josephson STM and Tedrow-Meservey-Fulde STM as tools to probe the superconducting and magnetic order parameters with unprecedented resolution at atomic length scales (1-3). We have shown that these methods can unravel new microscopic insights on novel quantum particles, such as the Majorana quasiparticle (5).

All of our microscopes are home-built systems that were developed in cooperation with leading cryogenics companies. Our unique STM measurement heads includes critical design aspects (6) to ensure highest mechanical stability and thermalization. At the same time, our microscopy modules are outfitted with optical access and multiple sample contacts, enabling the study of gate-tunable devices, such as made from moiré materials as well as the deposition of individual atoms on cold surfaces.  

Scanning Tunneling Microscopy with its ability to visualize individual wave functions is a key method for obtaining microscopic insights into the electronic structure and quasiparticle excitations of topological and correlated quantum materials at atomic length scales. On the other hand, for example, the boundary modes of topological materials, such as integer and fractional topological and quantum anomalous Hall insulators occur at mesoscopic lengths scales on the order of 100 nm or more.

Hence, novel scanning probe methods that can detect mesoscopic electronic states, examine mesoscopic transport phenomena, and characterize the bulk-boundary correspondence of topologically gapped systems require novel scanning probe methods.

In our group, we focus on the development (1) and bottom-up implementation of novel scanning probe microscopy methods for operation at millikelvin temperatures. A particular emphasis is the development of mechanically stable (2) microscopy modules utilizing microwave read-outs that permit the operation inside a dry dilution refrigerator system (3). Building on our expertise in cryogenic microscopy methods, we combine the development of novel nanopositioning technology, microscopy modules, and read-out methodologies to facilitate to new breakthroughs in quantum material research.

Our efforts in developing nanopositioning stages for application in dilution refrigerators already resulted in several pending patent applications as well as a spin-off company (4).

Related publications

(1) B. Jäck, Physical Review Research 2 , 043031 (2020
(2) C. Ast et al., Rev. Sci. Instrum. 79, 093704 (2008)
(3) M.E. Barber et al., J. Low Temp. Phys. 215, 1-23 (2024).
(4) Quano Technologies Limited, www.quano-tech.com