Dresden 2017 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 41: Correlated Electrons: Quantum-Critical Phenomena

TT 41.11: Vortrag

Mittwoch, 22. März 2017, 12:15–12:30, HSZ 204

Signature of frustrated moments in quantum critical CePd_1−xNi_xAl — Akito Sakai¹, Stefan Lucas², Zita Huesges², Kai Grube³, Philipp Gegenwart¹, Oliver Stockert², Hilbert v. Löhneysen³, and •Veronika Fritsch¹ — ¹EP 6, Electronic Correlations and Magnetism, Augsburg University, Germany — ²Max Planck Insitute for Chemical Physics of Solids, Dresden, Germany — ³Institute for Solid State Physics and Physics Institute, Karlsruhe Institute of Technology, Germany

Magnetic frustration suppresses long-range magnetic order despite the presence of strong magnetic couplings. This results in exotic ground states, where the spins can fluctuate down to zero temperature. However, metallic materials that simultaneously exhibit magnetic frustration and a strong coupling between the magnetic moments and the conduction electrons, are quite scarce.

The here presented CePdAl is a system were the Kondo effect and magnetic frustration coexist. It can be tuned across a quantum critical point by substitution of Pd with approximately 14% of Ni. Furthermore, field-induced quantum criticality can be observed in CePd_1−xNi_xAl. We have investigated single crystals with Ni concentrations 0 ≤ x ≤ 0.16. In addition to the generic signatures of quantum criticality a unique thermodynamic feature of the frustrated moments, i.e. an additional contribution to the magnetic Grüneisen paramter, is discovered [1].

[1] A. Sakai et al., ArXiv:1609.00816 [cond-mat.str-el] (2016).