Pressure-Driven Quantum Criticality and T/H Scaling in the Icosahedral Au-Al-Yb Approximant

Abstract

We report on ac magnetic susceptibility measurements under pressure of the Au-Al-Yb alloy, a crystalline approximant to the icosahedral quasicrystal that shows unconventional quantum criticality. In describing the susceptibility as $\chi (T{)}^{-1}-\chi (0{)}^{-1}\propto T^{\gamma }$, we find that $\chi (0{)}^{-1}$ decreases with increasing pressure and vanishes to zero at the critical pressure $P_{\mathrm{c}}\simeq 2$ GPa, with $\gamma (\simeq 0.5)$ unchanged. We suggest that this quantum criticality emerges owing to critical valence fluctuations. Above $P_{\mathrm{c}}$, the approximant undergoes a magnetic transition at $T\simeq 100$ mK. These results are contrasted with the fact that, in the quasicrystal, the quantum criticality is robust against the application of pressure. The applicability of the so-called $T/H$ scaling to the approximant is also discussed.

11 pages, 5 figures

References in corpus (8)

• Quantum critical state in a magnetic quasicrystal
• Multiple energy scales at a quantum critical point
• Quantum Valence Criticality as Origin of Unconventional Critical Phenomena
• Roles of Critical Valence Fluctuations in Ce- and Yb-Based Heavy Fermion Metals
• Strange metal without magnetic criticality
• Non-Fermi-Liquid Behavior in Metallic Quasicrystals with Local Magnetic Moments
• Pressure-Induced Valence Crossover and Novel Metamagnetic Behavior near the Antiferromagnetic Quantum Phase Transition of YbNi${}_3$Ga${}_9$
• T/B Scaling in beta-YbAlB4

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• Unveiling the Physics of the Mutual Interactions in Paramagnets
• Variation of Pressure-Induced Valence Transition with Approximation Degree in Yb-Based Quasicrystalline Approximants
• The Aubry-Andre Anderson model: Magnetic impurities coupled to a fractal spectrum
• On anomalous temperature dependence of relaxation rate measured by \muSR in α-YbAl_{0.986}Fe_{0.014}B_4
• New Quantum Criticality Revealed under Pressure
• Non-Divergent Grüneisen Parameter in Quantum Critical Quasicrystal Yb${}_{15}$Al${}_{34}$Au${}_{51}$: Reflection of Robustness of Quantum Criticality under Pressure
• Interpretation of some Yb-based valence-fluctuating crystals as approximants to a dodecagonal quasicrystal
• Anomalous magnetic transition in a disordered quasicrystal approximant with heavy-fermion nature
• Elastic Softening in Quantum Critical Yb-Al-Au Approximant Crystal and Quasicrystal
• Theory for Non-Fermi Liquid Temperature Dependence in Resistivity of Ce_xLa_{1-x} Cu_{5.62} Au_{0.38} (x=0.02-0.10) on the Local Quantum Valence Criticality of Ce Impurities
• Site-selective correlations in interacting "flat-band" quasicrystals