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ABSTRACT: Numerous phenomenological parallels have been drawn between f- and d-electron systems in an attempt to understand their display of unconventional superconductivity. The microscopics of how electrons evolve from participation in large moment antiferromagnetism to superconductivity in these systems, however, remains a mystery. Knowing the origin of Cooper paired electrons in momentum space is a crucial prerequisite for understanding the pairing mechanism. Of special interest are pressure-induced superconductors CeIn(3) and CeRhIn(5) in which disparate magnetic and superconducting orders apparently coexist-arising from within the same f-electron degrees of freedom. Here, we present ambient pressure quantum oscillation measurements on CeIn(3) that crucially identify the electronic structure-potentially similar to high-temperature superconductors. Heavy hole pockets of f-character are revealed in CeIn(3), undergoing an unexpected effective mass divergence well before the antiferromagnetic critical field. We thus uncover the softening of a branch of quasiparticle excitations located away from the traditional spin fluctuation-dominated antiferromagnetic quantum critical point. The observed Fermi surface of dispersive f-electrons in CeIn(3) could potentially explain the emergence of Cooper pairs from within a strong moment antiferromagnet.
Proceedings of the National Academy of Sciences 06/2009; 106(19):7741-4. · 9.68 Impact Factor
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N Harrison,
S E Sebastian,
C H Mielke,
A Paris,
M J Gordon,
C A Swenson,
D G Rickel,
M D Pacheco,
P F Ruminer,
J B Schillig,
J R Sims,
A H Lacerda,
M-T Suzuki, H Harima,
T Ebihara
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ABSTRACT: We report measurements of the de Haas-van Alphen effect in CeIn(3) in magnetic fields extending to approximately 90 T, well above the Néel critical field of mu(0)H(c) approximately 61 T. The unreconstructed Fermi surface a sheet is observed in the high magnetic field polarized paramagnetic limit, but with its effective mass and Fermi surface volume strongly reduced in size compared to that observed in the low magnetic field paramagnetic regime under pressure. The spheroidal topology of this sheet provides an ideal realization of the transformation from a "large Fermi surface" accommodating f electrons to a "small Fermi surface" when the f-electron moments become polarized.
Physical Review Letters 09/2007; 99(5):056401. · 7.37 Impact Factor
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ABSTRACT: AuZn undergoes a shape-memory transition at 67 K. The de Haas-van Alphen effect persists to 100 K enabling the observation of a change in the quantum oscillation spectrum indicative of a catastrophic Fermi surface reconstruction at the transition. The coexistence of both Fermi surfaces at low temperatures suggests an intrinsic phase separation in the bulk of the material. In addition, Dingle analysis reveals a sharp change in the scattering mechanism at a threshold cyclotron radius, attributable to the underlying microstructure driving the shape-memory effect.
Physical Review Letters 04/2005; 94(11):116401. · 7.37 Impact Factor
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ABSTRACT: Martensites are materials that undergo diffusionless, solid-state transitions. The martensitic transition yields properties that depend on the history of the material and may allow it to recover its previous shape after plastic deformation. This is known as the shape-memory effect (SME). We have succeeded in identifying the primary electronic mechanism responsible for the martensitic transition in the shape-memory alloy AuZn by using Fermi-surface measurements (de Haas-van Alphen oscillations) and band-structure calculations. This strongly suggests that electronic band structure is an important consideration in the design of future SME alloys.
01/2005;
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ABSTRACT: Angle-resolved de Haas–van Alphen measurements made on ThBe13 in pulsed magnetic fields are compared with Fermi surface predictions calculated by means of the linear augmented-plane-wave method with spin-orbit interactions. While all of the experimentally determined quasiparticle effective masses are light and of order the free electron mass, they are still roughly double those obtained from the calculated band structure, thereby being suggestive of the existence of notable electron-phonon interactions. The relevance of these de Haas–van Alphen results to strongly correlated UBe13 is also discussed.
Phys. Rev. B. 01/2000; 61(3).
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孝雄 海老原,
Suchitra E. Sebastian,
N. Harrison,
C. D. Batista,
S. A. Trugman,
V. Fanelli,
M. Jaime,
T. P. Murphy,
E. C. Palm, H. Harima,
Takao Ebihara
