UC Irvine

Novel phenomena in magnetically intercalated graphite have been the subject of much research, pioneered and promoted by M. S. and G. Dresselhaus and many others in the 1980s. Among the most enigmatic findings of that era was the dramatic, roller-coaster-like behavior of the magnetoresistivity in a EuC6 compound, in which magnetic Eu2+ ions form a triangular lattice that is commensurate to graphite honeycomb planes. In this study, we provide a long-awaited microscopic explanation of this behavior, demonstrating that the resistivity of EuC6 is dominated by spin excitations in Eu planes and their highly nontrivial evolution with the magnetic field. Together with our theoretical analysis, the present study showcases the power of the synthetic 2D materials as a source of potentially significant insights into the nature of exotic spin excitations.