Berlin 2024 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 5: Spin Structures and Magnetic Phase Transitions I

MA 5.6: Vortrag

Montag, 18. März 2024, 10:45–11:00, EB 202

The role of quantum fluctuations for the spin-flop transition in hematite — •Tobias Dannegger and Ulrich Nowak — Fachbereich Physik, Universität Konstanz

Hematite is a canted antiferromagnet with promising properties for spintronics applications such as long range spin transport. At higher temperatures, its equilibrium properties and phase transitions are well described by a semiclassical spin model, but towards low temperatures, qualitative differences between the predictions of a classical model and experimental results arise [1]. Here, we explore how quantum effects can account for those differences using mean-field calculations and exact diagonalisation of the quantum Heisenberg Hamiltonian. Based on an ab initio parametrised model, we compute low-temperature spin-flop fields and compare them to classical calculations and measurements on a hematite single-crystal.

[1] T. Dannegger et al., Phys. Rev. B 107, 184426 (2023).

Keywords: antiferromagnetic spintronics; quantum magnetism; hematite; morin transition