Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 5: Electron Theory of Magnetism

MA 5.6: Vortrag

Montag, 23. März 2009, 12:15–12:30, HSZ 103

Lifshitz transitions in FePt due to a canted magnetic field — •Hongbin Zhang and Manuel Richter — IFW Dresden, Helmholtzstraße 20, 01069 Dresden

By density functional calculations, we show that in L1₀ FePt, a canted magnetic field can induce changes of the topology of the Fermi surfaces. This is a new driving force for such electronic topological transitions (also called Lifshitz transition) besides pressure, doping, and magnetic field of arbitrary direction. To elucidate its effects, we estimate the variation of thermopower using a simple two-band model. It is shown explicitly, that due to interband scattering, thermopower would have singular behavior at such transitions. However, strong smearing by chemical disorder will make it hard to observe such anomalies experimentally.