Fluctuations in Planar Magnetotransport Due to Tilted Dirac Cones in Topological Materials

Fluctuationsin planar magnetotransport are ubiquitousin topologicalHgTe structures, in both tensile (topological insulator) and compressivelystrained layers (Weyl semimetal phase). We show that the common reasonfor the fluctuations is the presence of tilted Dirac cones combinedwith the formation of charge puddles. The origin of the tilted Diraccones is the mix of the Zeeman term due to the in-plane magnetic fieldand quadratic contributions to the dispersion relation. We developa network model that mimics the transport of tilted Dirac fermionsin the landscape of charge puddles. The model captures the essentialfeatures of the experimental data. It should be relevant for the interpretationof planar magnetotransport in a variety of topological and small bandgap materials.