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MA: Fachverband Magnetismus
MA 54: Spin: Transport, Orbitronics and Hall Effects II
MA 54.7: Vortrag
Donnerstag, 19. März 2020, 16:45–17:00, HSZ 403
Record-breaking Magnetoresistance at the Edge of a Microflake of Natural Graphite — •Christian Eike Precker1, José Barzola-Quiquia1, Pablo David Esquinazi1, Markus Stiller1, Mun Chan2, Marcelo Jaime2, Zhipeng Zhang3, and Marius Grundmann3 — 1Division of Superconductivity and Magnetism, Felix Bloch Institute, University of Leipzig, Leipzig, Germany. — 2National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos NM, USA. — 3Semiconductor Physics Group, Felix Bloch Institute, University of Leipzig, Leipzig, Germany.
Using reactive ion etching on a micrometer-sized Sri Lankan natural graphite sample, sharp edges were created and several electrodes were placed parallel to the c axis at distances comparable to the size of the internal crystalline regions. Electrical transport measurements in this configuration revealed record values for the change of the resistance under applied magnetic field. At low temperatures and at B ∼ 21 T the magnetoresistance (MR) reaches ∼ 107 %. The MR values exceed by far all earlier reported ones for graphite and they are comparable or even larger (at T > 50 K) than the largest reported in solids including the Weyl semimetals. The origin of this large MR lies in the way the electrodes were build, sensing regions with the existence of highly conducting 2D interfaces aligned, parallel to the graphene planes.