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Gaku Eguchi, S. Paschen:
"Exact magnetotransport analysis";
Poster: New Trends in Topological Insulators 2017, Monte Verità, Switzerland; 16.07.2017 - 21.07.2017.

Electric and spin transport are considered as the easiest accessible probes for researches of excited states, and transport phenomena originating from novel topological electronic phases are essentially understood with the Drude theory. Nevertheless, difficulties of the theory under finite magnetic fields have been recognized early in 1970s, and analyses of magnetotransport are typically unreliable because of the large number of open parameters [1].
Recently, we have established a new analysis scheme for two independent conduction channels that strongly reduces the numerical uncertainty [2]. It clarifies the exact physical meaning of the charge neutrality and of the non-saturating huge linear transverse magnetoresistance. In this presentation we explain details and demonstrate feasible transport behaviour under the condition. From the scheme upper limit of the transverse magnetoresistance has also been revealed. Remarkably, none of the topologically non-trivial insulators or semimetals, even in the recently highlighted Dirac line-node semimetals, violates the limit. We discuss its physical meaning as well as feasible transport behaviour in realistic bases. We also present several examples including bismuth thin film, a thermoelectric material, and three-dimensional topological insulators [2, 3].