On the Spin Fluctuation-Enhanced Specific Heat around the Magnetic Instabilities

Ishigaki, Aya; Moriya, Tôhru

doi:10.1143/jpsj.68.3673

Cited by 12 publications

(27 citation statements)

References 12 publications

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“…2 and Ref. [6,30]). Near the QTCP, because χ(q, ω) has two peaks around q = 0 and q = Q, we can express the specific heat as…”

Section: Specific Heatmentioning

confidence: 97%

“…Once the singularities of χ Q and χ 0 are determined, we can determine the singularities of a 0 by using eq. (30). Hereafter, by using the above self-consistent equations, we clarify how the susceptibilities and the magnetization measured from the QTCP (χ Q , χ 0 , δa 0 ≡ a 0 − a 0t with a 0t being the value at the QTCP) are scaled with δH = H − H t and T near the QTCP.…”

Section: Spin Fluctuation Theory For Quantum Tricritical Pointmentioning

confidence: 99%

“…The four SCR parameters (T 0A , T 00 , T QA , and T Q0 ) are control parameters; the five parameters (v, r QH , r 0H , H t , and a 0t ) are also control parameters, whereas once these parameters are fixed, the other parameters (r 0 , r Q , u 0 , and u Q ) are determined from the conditionsr Q (0, H t ) = 0,ũ Q (0, H t ) = 0 and eqs. (30), (31). Therefore, the number of control parameters is nine in the self-consistent equations.…”

Section: Choice Of Phenomenological Parametersmentioning

confidence: 99%

See 2 more Smart Citations

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh₂Si₂, CeRu₂Si₂, and β-YbAlB₄

2009

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We propose a phenomenological spin fluctuation theory for antiferromagnetic quantum tricritical point (QTCP), where the first-order phase transition changes into the continuous one at zero temperature. Under magnetic fields, ferromagnetic quantum critical fluctuations develop around the antiferromagnetic QTCP in addition to antiferromagnetic ones, which is in sharp contrast with the conventional antiferromagnetic quantum critical point. For itinerant electron systems, we show that the temperature dependence of critical magnetic fluctuations around the QTCP are given as χQ ∝ T −3/2 (χ0 ∝ T −3/4 ) at the antiferromagnetic ordering (ferromagnetic) wave number q = Q (q = 0). The convex temperature dependence of χ −1 0 is the characteristic feature of the QTCP, which is never seen in the conventional spin fluctuation theory. We propose that the general theory of quantum tricriticality that has nothing to do with the specific Kondo physics itself, solves puzzles of quantum criticalities widely observed in heavy-fermion systems such as YbRh2Si2, CeRu2Si2, and β-YbAlB4. For YbRh2Si2, our theory successfully reproduces quantitative behaviors of the experimental ferromagnetic susceptibility and the magnetization curve by choosing the phenomenological parameters properly. The quantum tricriticality is also consistent with singularities of other physical properties such as specific heat, nuclear magnetic relaxation time 1/T1T , and Hall coefficient. For CeRu2Si2 and β-YbAlB4, we point out that the quantum tricriticality is a possible origin of the anomalous diverging enhancement of the uniform susceptibility observed in these materials.

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“…2 and Ref. [6,30]). Near the QTCP, because χ(q, ω) has two peaks around q = 0 and q = Q, we can express the specific heat as…”

Section: Specific Heatmentioning

confidence: 97%

Section: Spin Fluctuation Theory For Quantum Tricritical Pointmentioning

confidence: 99%

Section: Choice Of Phenomenological Parametersmentioning

confidence: 99%

See 1 more Smart Citation

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh₂Si₂, CeRu₂Si₂, and β-YbAlB₄

2009

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“…13) However, these theories do not appear to have a firm microscopic basis 14) as compared to the conventional theory for magnetic QCP. [15][16][17][18][19] In this Letter, we propose a more natural explanation based on the Fermi liquid description of heavy fermions supported by the concept of the critical valence transition of the Ce ion under pressure.…”

mentioning

confidence: 96%

True Meaning of “Localized” f-Electrons Measured by dHvA Experiments in Ce-Based Heavy Fermion Metals

Miyake

Ikeda

2006

J. Phys. Soc. Jpn.

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The true meaning of the terms ''localized'' and ''itinerant'', frequently used in the interpretations of de Haas-van Alphen (dHvA) experiments of Ce-based heavy fermion metals, is argued. If the magnetic field H used in a dHvA measurement is larger than the threshold value of the order of the hybridization gap, the majority band of the quasiparticles would be filled up, and the Fermi surface (FS) would shift to the surface on which the conduction electrons have the Fermi energy without H. Then, the total number of electrons wrapped by the FS appears to decrease by one (f) electron per unit cell of the lattice. This phenomenon has been regarded as the ''localization'' of f-electrons, although f-electrons are never localized. As explicit examples, the transformation of the FS in CeRhIn 5 and CeIn 3 under pressure and that in CeRu 2 Si 2 near a pseudo-metamagnetic transition are discussed.

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“…(1). 6,15,16) In critical phenomena, long wavelength |q| ≪ q c around the magnetically ordered vector Q and the low-frequency |ω| ≪ ω c regions play dominant roles with q c and ω c being the cutoffs for the momentum and frequency, respectively. Hence, the coefficients Ω i for i = 2, 4 in Eq.…”

Section: Formalism Of the Scr Theorymentioning

confidence: 99%

Grüneisen Parameter and Thermal Expansion by the Self-Consistent Renormalization Theory of Spin Fluctuations

Watanabe

Miyake

2018

J. Phys. Soc. Jpn.

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The thermal expansion coefficient α and the Grüneisen parameter Γ near the magnetic quantum critical point (QCP) are derived on the basis of the self-consistent renormalization (SCR) theory of spin fluctuation. From the SCR entropy, the specific heat C V , α, and Γ are shown to be expressed in a simple form as) are related with each other. As the temperature T decreases, C a , α b , and Γ b become dominant in C V , α, and Γ, respectively. The inverse susceptibility of spin fluctuation coupled to the volume V in Γ b is found to give rise to the divergence of Γ at the QCP for each class of ferromagnetism and antiferromagnetism (AFM) in spatial dimensions d = 3 and 2. This V-dependent inverse susceptibility in α b and Γ b contributes to the T dependences of α and Γ, and even affects their criticality in the case of the AFM QCP in d = 2. Γ a is expressed aswith T 0 being the characteristic temperature of spin fluctuation, which has an enhanced value in heavy electron systems.

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On the Spin Fluctuation-Enhanced Specific Heat around the Magnetic Instabilities

Cited by 12 publications

References 12 publications

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh₂Si₂, CeRu₂Si₂, and β-YbAlB₄

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh₂Si₂, CeRu₂Si₂, and β-YbAlB₄

True Meaning of “Localized” f-Electrons Measured by dHvA Experiments in Ce-Based Heavy Fermion Metals

Grüneisen Parameter and Thermal Expansion by the Self-Consistent Renormalization Theory of Spin Fluctuations

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On the Spin Fluctuation-Enhanced Specific Heat around the Magnetic Instabilities

Cited by 12 publications

References 12 publications

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh2Si2, CeRu2Si2, and β-YbAlB4

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh2Si2, CeRu2Si2, and β-YbAlB4

True Meaning of “Localized” f-Electrons Measured by dHvA Experiments in Ce-Based Heavy Fermion Metals

Grüneisen Parameter and Thermal Expansion by the Self-Consistent Renormalization Theory of Spin Fluctuations

Contact Info

Product

Resources

About

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh₂Si₂, CeRu₂Si₂, and β-YbAlB₄

Spin Fluctuation Theory for Quantum Tricritical Point Arising in Proximity to First-Order Phase Transitions: Applications to Heavy-Fermion Systems, YbRh₂Si₂, CeRu₂Si₂, and β-YbAlB₄