Month: November 2017

07.11.2017 – Visit of Dr. Oliver Breunig

We welcome today Dr. Oliver Breunig from the Institute of Physics II at the University of Cologne, hosted by TWIST. He will give a talk on “Gigantic Negative Magnetoresistance in a Disordered Topological Insulator”.

Details: “Recently the phenomenon of negative magnetoresistance (MR) is attracting renewed interest due to its occurrence in Weyl semimetals because of the chiral anomaly. In other systems a large MR typically relates to magnetism. In this talk a novel mechanism leading to a large negative MR will be presented that is based not on magnetism, but on disorder. In the newly synthesized bulkinsulating topological insulator material T1BixSb1-xTe2 we find a suppression of the resistivity by up to 98 % in 14 T at low temperature. From transport data and numerical simulations, this gigantic negative MR is understood by a percolation of charge puddles formed in the disordered bulk.”

Click here to see the announcement.