The Waterloo Institute for Nanotechnology (WIN) and the Center for Nanointegration Duisberg-Essen (CENIDE) are pleased to present Thomas Michely, Professor of experimental physics at the II. Physikalisches Institut of Universität zu, for a joint 2D-MATURE seminar titled "Physics with a new type of 1D metal".
Date & Time: January 30 @ 10 AM
Physics with a new type of 1D metal
Abstract
A mirror twin boundary in a single layer of MoS2 is an extremely well insulated straight wire with a
diameter below 1 nm. The one-dimensional (1D) band linked to the wire originates from the necessity
to compensate polarization charge arising at discontinuities in the polar MoS2. Using scanning
tunneling spectroscopy, we determine the polarization charge to be 2/3 of an electron per unit cell along
the boundary in full agreement with theoretical predictions. While mirror twin boundaries are obstacles
for transport normal to them, they can successfully be applied as ultimately thin gates in field effect
transistors.
On the fundamental side, mirror twin boundaries can be used to construct a new type of Kondo system,
for which the entire spectral function is resolved, including the impurity levels underlying the resonance.
Using this information, with the help of numerical renormalization group calculations one is able to test
the predictive power of the Anderson model with high accuracy.
A second topic addressed is the use of molecular beam epitaxy to overcome the limitations set by the
approach of creating 2D materials through exfoliation from bulk crystals. While a rich world of new 2D
materials opens, we exemplify for the case of CrxSy 2D materials the difficulties to determine the
structure of the material and how density functional theory may lay out misleading traces.
Biography
Thomas Michely is professor for experimental physics at the II. Physikalisches Institut of Universität zu
Köln, Germany. He synthesizes nanostructures and 2D materials and is investigates their structural,
electronic, and magnetic properties. Key methods of his research are scanning tunneling microscopy
and -spectroscopy. He studied physics at the University Bonn where he received his PhD in 1991. He
has been working at the Research Center Jülich (until 1997) and at RWTH Aachen (until 2006). In
1994 he stayed at the IBM T.J. Watson Research Center with a Feodor-Lynen-Fellowship and from
1997-2001 he was a Heisenberg-Fellow of the German Science Foundation (DFG). His own work, but
also the work of his students won several prizes, among them the Wayne B. Nottingham Prize, the
Gerhard Ertl Young Investigator Award, and the Gaede Preis. He authors more than 200 publications
and holds 2 patents. His work received 16700 citations with an H-index 63 (google scholar).