Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/241478
Type: Artigo
Title: Conduction electron spin resonance in the alpha-Yb1-xFexAlB4 (0 <= x <= 0.50) and alpha-LuAlB4 compounds
Author: Holanda, L. M.
Lesseux, G. G.
Magnavita, E. T.
Ribeiro, R. A.
Nakatsuji, S.
Kuga, K.
Fisk, Z.
Oseroff, S. B.
Urbano, R. R.
Rettori, C.
Pagliuso, P. G.
Abstract: beta-YbAlB4 has become one of the most studied heavy fermion systems since its discovery due to its remarkable physical properties. This system is the first reported Yb-based heavy-fermion superconductor (HFS) for which the low-T superconducting state emerges from a non-fermi-liquid (NFL) normal state associated with quantum criticality Nakatsuji et al 2008 Nature 4 603. Additionally, it presents a striking and unprecedented electron spin resonance (ESR) signal which behaves as a conduction electron spin resonance (CESR) at high temperatures and acquires features of the Yb3+ local moment ESR at low temperatures. The latter, also named Kondo quasiparticles spin resonance (KQSR), has been defined as a 4f-ce strongly coupled ESR mode that behaves as a local probe of the Kondo quasiparticles in a quantum critical regime, Holanda et al 2011 Phys. Rev. Lett. 107 026402. Interestingly, beta-YbAlB4 possesses a previously known structural variant, namely the alpha-YbAlB4, phase which is a paramagnetic Fermi liquid (FL) at low temperatures Macaluso et al 2007 Chem. Mater. 19 1918. However, it has been recently suggested that the alpha-YbAlB4 phase may be tuned to NFL behavior and/or magnetic ordering as the compound is doped with Fe. Here we report ESR studies on the alpha-Yb1-xFexAlB4 (0 <= x <= 0.50) series as well as on the reference compound alpha-LuAlB4. For all measured samples, the observed ESR signal behaves as a CESR in the entire temperature range (10K less than or similar to T less than or similar to 300 K) in clear contrast with what has been observed for beta-YbAlB4. This striking result indicates that the proximity to a quantum critical point is crucial to the occurrence of a KQSR signal.
beta-YbAlB4 has become one of the most studied heavy fermion systems since its discovery due to its remarkable physical properties. This system is the first reported Yb-based heavy-fermion superconductor (HFS) for which the low-T superconducting state emerges from a non-fermi-liquid (NFL) normal state associated with quantum criticality Nakatsuji et al 2008 Nature 4 603. Additionally, it presents a striking and unprecedented electron spin resonance (ESR) signal which behaves as a conduction electron spin resonance (CESR) at high temperatures and acquires features of the Yb3+ local moment ESR at low temperatures. The latter, also named Kondo quasiparticles spin resonance (KQSR), has been defined as a 4f-ce strongly coupled ESR mode that behaves as a local probe of the Kondo quasiparticles in a quantum critical regime, Holanda et al 2011 Phys. Rev. Lett. 107 026402. Interestingly, beta-YbAlB4 possesses a previously known structural variant, namely the alpha-YbAlB4, phase which is a paramagnetic Fermi liquid (FL) at low temperatures Macaluso et al 2007 Chem. Mater. 19 1918. However, it has been recently suggested that the alpha-YbAlB4 phase may be tuned to NFL behavior and/or magnetic ordering as the compound is doped with Fe. Here we report ESR studies on the alpha-Yb1-xFexAlB4 (0 <= x <= 0.50) series as well as on the reference compound alpha-LuAlB4. For all measured samples, the observed ESR signal behaves as a CESR in the entire temperature range (10K less than or similar to T less than or similar to 300 K) in clear contrast with what has been observed for beta-YbAlB4. This striking result indicates that the proximity to a quantum critical point is crucial to the occurrence of a KQSR signal.
Subject: Férmions pesados
Fermi, Teoria de líquidos de
Compostos intermetálicos
Country: Reino Unido
Editor: Institute of Physics Publishing
Citation: Conduction Electron Spin Resonance In The Alpha-yb1-xfexalb4 (0 <= X <= 0.50) And Alpha-lualb4 Compounds. Iop Publishing Ltd, v. 27, p. Jul-2015.
Rights: fechado
Identifier DOI: 10.1088/0953-8984/27/25/255601
Address: https://iopscience.iop.org/article/10.1088/0953-8984/27/25/255601
Date Issue: 2015
Appears in Collections:IFGW - Artigos e Outros Documentos

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