Quantum Criticality and Scaling of the Magnetic Response in CeCu6−x Aux

Autor:	W. Schmidt, M. Loewenhaupt, Hilbert von Löhneysen, M. Enderle, Oliver Stockert
Rok vydání:	2010
Předmět:	Quantum phase transition Physics Condensed matter physics General Materials Science Condensed Matter Physics Magnetic quantum number Scaling Spin quantum number Atomic and Molecular Physics and Optics Inelastic neutron scattering Spin-½ Spin magnetic moment Magnetic field
Zdroj:	Journal of Low Temperature Physics. 161:55-66
ISSN:	1573-7357 0022-2291
DOI:	10.1007/s10909-010-0210-7
Popis:	The heavy-fermion system CeCu6−x Au x which exhibits antiferromagnetic order for Au concentrations x>0.1, can be easily tuned to a quantum phase transition, either by chemical composition, i.e., Au concentration, or by an external magnetic field. We present extensive inelastic neutron scattering measurements in order to study the momentum and energy dependence of the critical spin fluctuations for concentration- and magnetic field-tuned CeCu6−x Au x . The quasi-2D fluctuations, observed for x=0.1 at the magnetic instability, are already present in pure CeCu6 and persist to x=0.2, i.e., well into the magnetically ordered regime. This is a strong hint that disorder does not play a major role in this system. The magnetic response for quantum critical CeCu6−x Au x exhibits critical slowing down and obeys scaling relations that depend on the tuning parameter. While the E/T scaling of the dynamic susceptibility in concentration-tuned CeCu5.9Au0.1 is an indication for local quantum criticality, the E/T 3/2 scaling in field-tuned CeCu5.8Au0.2 points to a conventional spin-density-wave instability.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d90f1d47f5bb1bfad5477ac1e9fe4300 https://doi.org/10.1007/s10909-010-0210-7 Zobrazit plný text záznamu Plný text ve formátu PDF