Welcome to the workgroup of Prof. Möller

Surface Science Let's have a look at atoms and molecules!

Welcome to the site of the Möller Group!

Surfaces are of major importance in daily life. On the one hand friction allows us to run or to drive a car; on the other hand it causes that costy energy is degraded to heat which is dissipated. Chemical processes at surfaces lead as well to corrosion as to catalytic reactions. Furthermore surfaces and interfaces are becoming more and more important for the development of devices in microelectronics if the size is reduced to the nanometer scale.

In our group surfaces and interfaces are studied by various microscopic and spectroscopic techniques.

News

3 dimensional representation of the Bi2Se3 surface. The potential is superimposed as colour infomation.

03. May 2016 Nanoscale transport in topological insulators

The edge is only 1 nm high, but that is enough to discuss the transport properties at the surface of 3D  topological insulators (TI): Christian Bobisch' and Sebastian Bauers research on nanoscale transport at the surface of a 3D topological insulator got recently published in Nature Communications. In particular, we could show that step edges at the surface of a Bi2Se3 thin film have an impact to the nanoscale charge transport. Thereby, each surface step edge can be understood as a local resistance on the nanoscale which which in sum decrease the conductivity. However, this may also allow us to design the transport propetries at the TI surface with nanoscale precision.

The result were recently published under: S. Bauer and C.A. Bobisch, Nature Comm. 7, 11381 (2016)

STM topography of both CO phases. The transition is triggered by the electric field of the STM tip.

10.February 2016 Steering structural phase transitions of CO monolayers

Our reserach on CO monolayers on Cu(111) got published in the journal NanoLetters. In particular we find, that the electric field between the STM tip and the sample surface can selectively tune the ordering of a CO monolayer on Cu(111). Thereby, a phase transition between two ordered structural CO phases is induced. Moreover, the control by the STM tip also allows to write arbitrary patterns of the phases on the Cu(111) surface to create artificial potential landscapes with it. Together with our cooperation partners in San Sebastian and Barcelona, our results were recently published in the journal Nanoletters.

you can find the publication here

8.1.2015, New DFG-project studies topological insulators Newcomer in close inspection

They are the new star material in surface science: topological insulators (TI) were predicted some years ago and represent a new class of material with peculiar electronic properties. A recently started project lead by Christian Bobisch aims to analyze the charge current in the surface of a topological insulator with atomic resolution. The corresponding project “Analysis  of  the  Local  Electrochemical  Potential  of  Current  Carrying  Topological  Insulating Surfaces” is supported by the German research council (DFG) for the next two years.

Teaching Award 2014

25. June 2014 Teaching-Award 2014 for Christian Bobisch

On the occasion of this years "Dies Academicus",  Christian Bobisch was awarded a second award within short time. There he was awarded with the "Teaching Award of the University of Duisburg-Essen". This award is endowed with a price money of 5000 €, which is dedicated to further improve the teaching. For Christian Bobisch this award is especially important since the students themself, i.e. the student representatives, are nominating the awardees. At the ceremony, the development and the integration of new learing concepts and methods within the physics couse was honorably mentioned.

C.A. Bobisch

3. June 2014 Diversity-Involvement-Award for Christian Bobisch

On June, 3rd Dr. Christian Bobisch was awarded with the Diversity-Involvement-Award in the scope of the 2nd federal Diversity Day at the University of Duisburg-Essen. Prof. Wucher emphazied in his laudatio on his intense involvement within the pre-semester courses in physics, which garantee equal starting conditions for the students. This courses are especially beneficial for students which are somewhat handicapped by personal circumstances.

 

PTCDA adlayer on Bi/Cu(111)

4. April 2014 Publication in New Journal of Physics

In cooperation with the group of Prof. Enrique Ortega in San Sebastian, the results from the research stay of  Maren Cottin were recently published in The New Journal of Physics. There, we describe the robustness of the spin-polarised surface state at the Bi induced surface reconstruction on Ag(111) und Cu(111). Using a combination of photon-electron-spectroskopy and STM measurements, we show that the surface state stays  unaltered even after the adsorption of self organized molecular layers (C60, PTCDA, FeOEP).

You can find the publication here : "A chemically inert Rashba split interface electronic structure of C60, FeOEP and PTCDA on BiAg2/Ag(111) substrate", New J. Phys. 16 045002  (2014).

Cenide Best Paper

28.11.2013 Best Paper Award for Maren Cottin and Johannes Schaffert

This years CENIDE Best Paper Award 2013 goes to Maren Cottin and Johannes Schaffert from the group of Rolf Möler and Christian Bobisch for their publication entitled "Imaging the dynamics of individually adsorbed molecules" in Nature Materials. The young investigators were awarded with a certificate and prize money presented to them by Prof. Dr. Christof Schulz, scientific director of CENIDE.

Press release (in German)...

Bi(111) surface with LDOS standing wave pattern

Publication in Nanoletters

The interference of incomming and reflected waves is know to create a standing wave pattern. Moreover, also the interference of transmitted and forward scattered waves can create such a pattern.  In our latest publication in Nanoletters the PhD students Maren Cottin and johannes Schaffert show that one can observe such a strange scenario at the surface of bismuth (111). For this case, the scattering of electrons in the Bi(111) surface state was analysed by means of scanning tunneling spectroscopy revealing the involved scattering processes.

Best Poster Dutch

30.April 2013 Best Poster Award for Maren Cottin and Ebru Özen

On this years Dutch Scanning Probe Day in Eindhoven Maren Cottin und Ebru Özen could impress the attending  scientists with their poster presentation. Bost students fom the Möller group were awarded with the "Best Poster Award" for the their poster entitled "The Detection of Light Emitted from the Tunneling Junction of a Low T emperature-STM". At the end of an exciting conference the organizor Prof. Paul Koenraad handed the price over to Ebru Özen  and Maren Cottin.

Nature Materials

Publication in Nature Materials

Our work on the motion of single molecules visualized by a new STM based technique got accepted by Nature Materials.

Johannes Schaffert and Maren Cottin together with the project leaders Christian Bobisch and Rolf Möller are presenting their research in the high impact journal "Nature Materials". In this work the motion of single adsorbed molecules is monitored by STM. Our new STM based technique allows us to spatially map the probability of exciting a molecular motion by injecting tunneling electrons. The resulting excitation maps are gathered simultaneoulsy to the topographic information and thus offer the same ultimate spatial resolution. This approach opens a new route to analyze the motion of single molecules or atoms with atomic resolution.

link to the publication

Poster-alle

27.7.2012 Best Poster Award for Maren Cottin

Maren Cottin received the Best Poster Award at the 2012 International Conference on Nanoscience and Nanotechnology.

more...