Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 100: Frustrated Magnets - Pyrochlore Oxides

TT 100.1: Vortrag

Donnerstag, 15. März 2018, 15:30–15:45, H 3005

Orientation Dependence of the Magnetic Phase Diagram of Yb₂Ti₂O₇ — •Steffen Säubert^1,2, Christopher Duvinage¹, Allen Scheie³, Jonas Kindervater³, Hitesh Changlani³, Shu Zhang³, Seyed Koohpayeh³, Oleg Tchernyshyov³, Collin Broholm^3,4,5, and Christian Pfleiderer¹ — ¹Physik Department, Technische Universität München, Germany — ²Heinz Maier-Leibnitz Zentrum, Technische Universität München, Germany — ³Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University, USA — ⁴NIST Center for Neutron Research, National Institute of Standards and Technology, USA — ⁵Department of Materials Science and Engineering, Johns Hopkins University, USA

The magnetic pyrochlore oxide Yb₂Ti₂O₇ received a lot of attention in recent years, as strong transverse quantum fluctuations significantly influence the system, and since the nature of its ground state is still under debate to host a spin liquid quantum state, i.e. quantum spin ice, at low temperatures. We report the orientation dependence of the magnetic phase diagram of Yb₂Ti₂O₇, inferred from magnetometry down to millikelvin temperatures, and further address the question of the ground state of Yb₂Ti₂O₇. The magnetic phase diagram for externally applied field shows an unusual field dependence of a first-order phase boundary, notably an applied field initially increases the ordering temperature when applied parallel to the crystalline ⟨ 111 ⟩ or ⟨ 110 ⟩ axes. This unusual field dependence is absent for field along ⟨ 100 ⟩. The zero-field ground state was found to be of ferrimagnetic order, with spins slightly splayed away from one of the six ⟨ 100 ⟩ directions.