Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 25: Correlated Electrons: Quantum-Critical Phenomena 1

TT 25.9: Vortrag

Mittwoch, 28. März 2012, 11:45–12:00, H 3010

Pressure dependence of the topological Hall effect in MnSi — •Robert Ritz, Marco Halder, Christian Franz, Michael Wagner, Andreas Bauer, Christoph Schnarr, and Christian Pfleiderer — Physik Department E21, Technische Universität München, D-85748 Garching, Germany

The observation of a topological Hall signal in the A-phase of MnSi [1] provides unambiguous, quantitative evidence of the non-trivial topology of the skyrmion lattice first inferred from small angle neutron scattering [2]. We report a comprehensive study of the pressure dependence of the topological Hall signal in MnSi. We connect the behaviour reported for the pressure range 6 to 12 kbar [3] with the properties at ambient pressure and explore the importance of various aspects of the experimental set up. Careful temperature and field dependent measurements reveal that the topological Hall signal in MnSi increases monotonically from 4 n Ω cm at ambient pressure and appears to limit at a large intrinsic value of ∼ 50 n Ω cm as the helimagnetic transition temperature decreases.
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