Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 41: Frustrated Magnets - Spin Liquids - Experiments

TT 41.7: Vortrag

Dienstag, 13. März 2018, 12:00–12:15, H 3005

NMR investigations on doped kagomé lattice mott insulator Ga_xCu_4−x(OD)₆Cl₂ — •Ranjith Kumar Kizhake Malayil¹, Pascal Puphal², Cornelius Krellner², and Michael Baenitz¹ — ¹Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany — ²Institute of Physics, Goethe- University Frankfurt, 60438 Frankfurt am Main, Germany

Herbertsmithite (ZnCu₃(OH)₆Cl₂),[1] which is reported as a prototype kagome quantum spin liquid (QSL) triggers the search for new QSL materials among its polymorphs. Replacing the divalent Zn by the trivalent Ga was proposed to form a new correlated Dirac-kagome metal combining Dirac electrons, strong interactions, and frustrated magnetism[2]. Polycrystalline samples of Ga_xCu_4−x(OD)₆Cl₂ were synthesized with Ga-doping level of 0 < x < 1. We have employed ^71,69Ga and ²H nuclear magnetic resonance (NMR) experiments together with bulk studies to explore the ground state properties of Ga_xCu_4−x(OD)₆Cl₂. Ga-NMR proof a homogeneous Ga distribution and narrow Ga-lines which is typical for Ga-based quantum magnets. Magnetic ordering is found to be suppressed with increasing Ga-concentration similar to that observed for Zn- Herbertsmithite. Spin-lattice relaxation measurement reveals the existence of a spin gap in the excitation spectrum which is increasing linearly with the applied field.
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I. Mazin et al., Nature Communications 5, 4261 (2014)