Research

Our overarching goal is to explore and understand new quantum states of electronic matter on the atomic scale. To do so, we use and develop novel spectroscopic-imaging scanning tunneling microscopy (SI-STM) tools to visualize the relevant quantum mechanical degrees of freedom.

Our goal is to build instruments and develop techniques that enable us to address the questions we find most interesting. This is possible thanks also to Milan’s broad background with different research themes and technologies: he learned his trade in Seamus Davis’ SI-STM lab and with Felix Baumberger, and later moved as an ETH fellow to Andreas Wallraff’s qudev lab where he investigated coupled cavity arrays in circuit QED. We further have group members with different background and interests, working together on physics and instrumentation.

Here are some themes and techniques that we currently work on:

Atmospheric Pollutans and Climate Change

Nanofabricated “Smart Tips”. One of the  projects back from my job-proposal is to develop nanofabricated STM tips. The idea behind these “smart tips” is to use the technologies that were developed over decades in nanofabrication and make them available for scanning probe by using a nano-device instead of the traditional STM tungsten tip. One gains the flexibility of using different functionalities that are known from the fields of nanofabrication and mesoscopic physics. We are collaborating with the group Simon Groeblacher at TU Delft to realize this concept, benefitting from their unparalleled micro/nano fabrication know how.  A prototype of a smart tip is shown to the left. See publications in Microsyst Nanoeng, Nanotechnology, and PRB.Josephson STM. Josephson STM has the ability to gain insight into spatial variations of the order parameter, or superfluid density. We have managed to, for the first time, use JSTM with atomic resolution on a quantum material.We have used atomic-resolution Josephson scanning tunneling microscopy to reveal a strongly inhomogeneous superfluid in the iron-based superco ductor FeTe0.55Se0.45. The results and their implications are published in Nature.

Global trade and Climate Change

Ultra-stable SI-STM instrument. For SI-STM, having the most stable STM head is key. We have used finite element simulations, good choices in material science, and craftsmanship to build the most stable STM head in the world, to our knowledge. See publication in RSI.Josephson STM. Josephson STM has the ability to gain insight into spatial variations of the order parameter, or superfluid density. We have managed to, for the first time, use JSTM with atomic resolution on a quantum material.We have used atomic-resolution Josephson scanning tunneling microscopy to reveal a strongly inhomogeneous superfluid in the iron-based superconductor FeTe0.55Se0.45. The results and their implications are published in Nature.