Scanning Tunneling Microscopy

 

Head:

Prof. Dr. phil. Richard Berndt

 

News:

Video EU project COSMICS

Feb 02, 2021

Cosmics

A cute video about our EU project COSMICS  is now available on YouTube.

Dr. Manuel Gruber accepted junior professorship

Jan 29, 2021

Dr. Manuel Gruber has accepted an offer for a junior professorship at the University Duisburg-Essen. At CAU, Manuel had joined the Berndt lab to lead a subgroup focussing on molecular magnetism. His work was essential for many collaborations between chemistry and physics in SFB 677. We wish Manuel continued success (and a wee bit nostalgia for Kiel :) )

New Concepts and Tools in Molecular Spintronics

Jan 29, 2021

A fundamental understanding of new smart functional molecules and concepts to use them for developing new components for electronic devices – that are the main aims of the project COSMICS “New Concepts and Tools in Molecular Spintronics”. Last week the international consortium met at Kiel University for the first time. The project brings together six teams of physicists and chemists from across Europe, including universities and research organisations from France, Spain and Denmark, and Kiel University from Germany. The project is being funded through the EU's HORIZON 2020 research programme with approximately 3.8 million Euro.

Link Article Uni Kiel (german)

Link Article Uni Kiel (english)

Link Article KinSIS (german)

Link Article KinSIS (english)

Austrian teachers visiting the IEAP

Jan 29, 2021

On 17 April 2019, a group of approximately 20 physics teachers from the Austrian Physical Society visited the Berndt group. After some general remarks on the research methodology and topics of the group, Dr. Gruber guided the group to our labs, showed our low-temperature scanning tunneling microscopes, and presented our project COSMICS (EU FET Horizon2020). The group turned out to be interested in a wide variety of aspects of the work, form basic physics over the techniques used to funding issues. Apparently our little show was much appreciated: we were rewarded by delicious ''Mozart Kugeln'' from Innsbruck.

Magnetoresistance of ''handmade'' dimers

Jan 29, 2021

Spin-orbit coupling links spin and momentum degrees of freedom by the Hamiltonian H = ξLS (L, S: orbital momentum and spin operators, ξ: coupling strength). It is the origin of phenomena such as magnetocrystalline anisotropy and anisotropic magnetoresistance, which are of fundamental interest and important for sensor applications. To tune spin-orbit coupling at a single atom, the high rotational symmetry of the atom should be reduced. Johannes Schöneberg, Alexander Weismann and Richard Berndt achieved this by constructing dimers from single Pb atoms on an Fe double layer substrate, whose domain pattern exhibits suitable magnetization directions. First-principles calculations by Paolo Ferriani and Stefan Heinze reveal the molecular orbitals that cause the large observed anisotropic magnetoresistance. The results are published in Physical Review B "Tunneling anisotropic magnetoresistance via molecular Pi orbitals of Pb dimers" and have been highlighted by an Editors' suggestion for papers that the editors and referees find of particular interest, importance, or clarity.

Conductance of a molecular wire

Jan 29, 2021

Plenty of publications report on the conductance of molecular wires between electrodes. Characterization of the junction geometry, however, is usually missing. We synthesized a molecule for low-temperature STM experiments that stands vertically on a substrate. Despite this reductionist approach, its conductance data turned out to be
complex. Calculations show that geometrical changes, orbital symmetries, and bond formation control the conductance. This joint work within SFB677 by
Torben Jasper-Tönnies, Aran Garcia-Lekue, Thomas Frederiksen, Sandra Ulrich, Rainer Herges, and Richard Berndt has recently been published in Physical Review Letters and highlighted as Editors' Selection.

Gaede Preis 2017 for Dr. Guillaume Schull

Jan 20, 2017

At the meeting of the condensed matter division of the German Physical Society Dr. Guillaume Schull will be awarded the Gaede Preis 2017 for the work performed in the Berndt group.

''Dr. Guillaume Schull wird ausgezeichnet für seine wegweisenden experimentellen Untersuchungen an elektrischen Kontakten zu einzelnen Molekülen und Atomen sowie zur Emission von Licht aus solchen Kontakten.''

Cooperation with successful postdoc of SFB 677 continues at international level

Jan 10, 2017

Although Yong-Feng Wang left Kiel University five years ago the cooperation with the colleagues from the SFB 677 and the group of Professor Richard Berndt at the Institute of Experimental and Applied Physics still continues. Most recently a joint paper about the vacuum synthesis was published as a cover story of the journal Chemical Communications. Since 2006 Wang worked as a postdoc in the group of Professor Berndt and was involved in numerous publications. 2012 Wang went to Peking University, by now he leads a group at the Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics himself.

In their paper the international group of scientists present tunneling microscopy and spectroscopy data from magnetic magnetic aluminum phthalocyanine (AlPc) which was prepared in ultrahigh vacuum using on-surface metalation from H2Pc. It turns out that AlPc remains paramagnetic on Au(111) with its spin density distributed over the isoindole lobes. “The vacuum synthesis is a powerful method to synthesize air-unstable molecules like the magnetic AlPc molecules we synthesised in our paper”, Wang explains. “In vacuum, the effect by air reactive molecules such as oxygen and water can be excluded.”

“Results like these show how international successful the early career scientists of our Collaborative Research Center are. I am very glad the cooperation with Yong-Feng Wang continues despite the distance between Peking and Kiel”, says Richard Berndt. “My time in Kiel was the most important period in my scientific career“, Wang sums up. “Here I learnt how to find important scientific questions, how to solve them, how to make high-quality scientific figures, and how to write high-level papers.” Since he left Kiel Wang came back for two longer research stays to work with Berndt again. In future, he hopes to set up an international cooperative lab to continue their collaborative work.

Original publication:

Vacuum synthesis of magnetic aluminum phthalocyanine on Au(111) I-Po Hong, Na Li, Ya-Jie Zhang, Hao Wang, Huan-Jun Song, Mei-Lin Bai, Xiong Zhou, Jian-Long Li, Gao-Chen Gu, Xue Zhang, Min Chen, J. Michael Gottfried, Dong Wang, Jing-Tao Lü, Lian-Mao Peng, Shi-Min Hou, Richard Berndt, Kai Wu and Yong-Feng Wang, Chem. Commun., 2016, 52, 10338-10341. DOI: 10.1039/C6CC03359H

35th Anniversary of Scanning Tunneling Microscopy

May 11, 2016

Reinhardt Schuhmann, editor of Physical Review Letters, recently presented a collection of articles to celebrate the 35th anniversary of scanning tunneling microscopy and the 30th anniversary of atomic force microscopy.

Among these papers is Surface-State Lifetime Measured by Scanning Tunneling Spectroscopy by Jiutao Li, Wolf-Dieter Schneider, Richard Berndt , O. R. Bryant, and S. Crampin, Phys. Rev. Lett. 81, 4464 (1998). It has been made free to read.

PhD thesis prize of the DPG Magnetism Division awarded to Manuel Gruber

Mar 16, 2016

During the recent meeting of the condensed matter division of the German Physical Society Dr. Manuel Gruber successfully competed for the PhD thesis prize of the magnetism division (ThyssenKrupp Electrical Steel PhD prize).

Manuel carried out his pioneering studies at the Karlsruhe Institute of Technology with Prof. Wulfhekel and the University of Strasbourg with Dr. Beaurepaire.  He explored the impact of molecules on the magnetic properties of inorganic substrates as well as the possibility to switch the magnetization of individual molecules adsorbed on surfaces.  As a postdoc with Prof. Berndt he is presently working  on related topics within SFB 677.