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Gegenwart, P.; Custers, J.; Tayama, Takashi; Tenya, Kenichi; Geibel, C.; Sparn, G.; Harrison, N.; Kerschl, P.; Eckert, D.; Müller, K.‐H.; Steglich, F.

doi:10.1023/a:1025624831341

Cited by 32 publications

(37 citation statements)

References 26 publications

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“…Thus it is a complementary case to YbRh 2 Si 2 . However in an external field there is no field induced transition to transverse AF order as one might naively expect from the model discussion, rather it is driven further away from the AF QCP as specific heat and resistivity measurements suggest [31]. There is however one known example of a heavy fermion system which exhibits field induced AF order, though complicated by the appearance of superconductivity.…”

Section: Discussionmentioning

confidence: 91%

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Field-induced quantum phase transition in the anisotropic Kondo necklace model

Thalmeier

Langari

2007

Phys. Rev. B

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The anisotropic Kondo necklace model in 2D and 3D is treated as a genuine model for magnetic to Kondo singlet quantum phase transitions in the heavy fermion (HF) compounds. The variation of the quantum critical point (QCP) with anisotropy parameters has been investigated previously in the zero field case [1]. Here we extend the treatment to finite fields using a generalised bond operator representation including all triplet states. The variation of critical tc with magnetic field and the associated phase diagram is derived. The influence of anisotropies and the different gfactors for localised and itinerant spins on the field dependence of tc is also investigated. It is found that three different types of behaviour may appear: (i) Destruction of antiferromangetism and appearance of a singlet state above a critical field. (ii) The inverse behaviour, namely field induced antiferromagnetism out of the Kondo singlet phase. (iii) Reentrance behaviour of the Kondo singlet phase as function of field strength.

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Section: Discussionmentioning

confidence: 91%

“…30. A recent example of a field induced destruction of AF order is the tetragonal YbRh 2 Si 2 compound [31]. At ambient pressure and zero field it has an AF order which is indeed of the easy plane (xy)-interaction type (δ=0).…”

Section: Discussionmentioning

confidence: 99%

Field-induced quantum phase transition in the anisotropic Kondo necklace model

Thalmeier

Langari

2007

Phys. Rev. B

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“…the Néel temperature vanishes at H c2 (0) [5,6]. Due to the weak magnetic anisotropy of CeCoIn 5 H m should vanish at the field induced QCP [1] as was observed in YbRh 2 Si 2 [28] and CeNi 2 Ge 2 [29]. For CeCoIn 5 , this may explain the existence of a large field domain between H c2 and H K where AF and F correlations compete.…”

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confidence: 95%

Evidence for a New Magnetic Field Scale inCeCoIn5

et al. 2006

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The Nernst coefficient of CeCoIn5 displays a distinct anomaly at H K ∼ 23 T. This feature is reminiscent of what is observed at 7.8 T in CeRu2Si2, a well-established case of metamagnetic transition. New frequencies are observed in de Haas-van Alphen oscillations when the field exceeds 23 T, which may indicate a modification of the Fermi surface at this field.PACS numbers: 75.30. Kz, 73.43.Nq, 71.27.+a Heavy-Fermion (HF) compounds [1] display a dazzling variety of physical phenomena which still lack a satisfactory general picture. The "non-Fermi-liquid" behavior emerging in the vicinity of a magnetic quantum critical point (QCP), associated with a continuous (i.e. secondorder) phase transition at zero temperature, has recently attracted much attention [2]. The case of the HF superconductor CeCoIn 5 [3] is intriguing. Magnetic field alters the normal-state properties of this system in a subtle way. In zero field, the system displays neither a T 2 resistivity nor a T -linear specific heat (standard features of a Landau Fermi liquid) down to the superconducting transition. When superconductivity is destroyed by the application of pressure [4] or magnetic field [5,6], the Fermi-liquid state is restored. In the latter case, the fieldtuned QCP identified in this way is pinned to the upper critical field, H c2 of the superconducting transition [7,8]. This is unexpected, not only because quantum criticality is often associated with the destruction of a magnetic order, but also because the superconducting transition becomes first order at very low temperatures [9]. The possible existence of a magnetic order with a field scale close to H c2 and accidentally hidden by superconductivity, has been speculated [6] but lacks direct experimental support.Comparing CeCoIn 5 with the well-documented case of CeRu 2 Si 2 [10, 11] is instructive. In the latter system a metamagnetic transition occurs at H m = 7.8 T: the magnetization jumps from 0.6 µ B to 1.2 µ B in a narrow yet finite window( ∆H m = 0.04 T in the T = 0 limit). The passage from an antiferromagnetically (AF) correlated system below H m to a polarized state dominated by local fluctuations above is accompanied by a sharp enhancement in the quasi-particle mass in the vicinity of H m which is thus akin to a field-tuned QCP. A sudden change of the Fermi surface (FS) topology across the metamagnetic transition has been established by de Hass-van Alphen (dHvA) effect studies [12], where new frequencies were detected above H m .In this letter, we report on two sets of experimental studies which indicate that the effect of the magnetic field on the normal-state properties of these two systems share some common features. They point to the existence of another field scale in CeCoIn 5 which has not been previously identified. By measuring the Nernst coefficient and studying quantum oscillations, we find compelling evidence that close to H K ∼ 23 T, the FS is modified. Therefore, in the T = 0 limit, CeCoIn 5 appears to display at least two distinct field scales.Single crystals of ...

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“…Unfortunately these scaling arguments do not permit a direct comparison with the field dependence of o (because of the T ¼ 0 extrapolation of the fit) to further our discussion of this parameter. The field dependence of A(H) for UBe 13 is stronger than in either CeNi 2 Ge 2 (where AðHÞ / H À0:6 ) or YbRh 2 Si 2 (where AðHÞ / 1=ðH À H c Þ) [18], two systems exhibiting different kinds of field-induced antiferromagnetic quantum critical points. The difference might be due to crystal symmetry (UBe 13 is cubic whereas CeNi 2 Ge 2 and YbRh 2 Si 2 are tetragonal) or because of the unformed nature of the antiferromagnetic state whose suppression causes the QCP.…”

Section: Discussionmentioning

confidence: 92%

Quantum criticality and the suppression of the heavy fermion state in UBe₁₃by high magnetic fields

Schmiedeshoff

Smith

2009

Philosophical Magazine

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We have measured the electrical resistivity of a single crystal of UBe 13 below 1 K and in high magnetic fields to 33 T. The resistivity exhibits the T 2 dependence characteristic of a Fermi liquid at low temperatures. The field dependence of the coefficient of the T 2 term in the resistivity suggests that the heavy fermion state is suppressed by high magnetic fields. We discuss these results in light of a proposed field-induced quantum critical point immersed in the novel superconducting state of this compound.

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Cited by 32 publications

References 26 publications

Field-induced quantum phase transition in the anisotropic Kondo necklace model

Field-induced quantum phase transition in the anisotropic Kondo necklace model

Evidence for a New Magnetic Field Scale inCeCoIn5

Quantum criticality and the suppression of the heavy fermion state in UBe₁₃by high magnetic fields

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Untitled

Cited by 32 publications

References 26 publications

Field-induced quantum phase transition in the anisotropic Kondo necklace model

Field-induced quantum phase transition in the anisotropic Kondo necklace model

Evidence for a New Magnetic Field Scale inCeCoIn5

Quantum criticality and the suppression of the heavy fermion state in UBe13by high magnetic fields

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Quantum criticality and the suppression of the heavy fermion state in UBe₁₃by high magnetic fields