Low-Frequency Spin Dynamics in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="normal">C</mml:mi><mml:mi mathvariant="normal">e</mml:mi><mml:mi>M</mml:mi><mml:msub><mml:mrow><mml:mi mathvariant="normal">I</mml:mi><mml:mi mathvariant="normal">n</mml:mi></mml:mrow><mml:mn>5</mml:mn></mml:msub></mml:math>Materials

Curro, N. J.; Sarrao, J. L.; Thompson, J. D.; Pagliuso, P. G.; Kos, Šimon; Abanov, Ar.; Pines, David

doi:10.1103/physrevlett.90.227202

Cited by 54 publications

(46 citation statements)

References 29 publications

(53 reference statements)

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“…Rather, K HF begins to deviate below 9 K, exhibits a maximum at 8 K and then decreases down to T N . This temperature of the breakdown of scaling corresponds well with the onset of antiferromagnetic correlations observed by inelastic neutron scattering and NMR spin lattice relaxation measurements (33,34). The physical picture that emerges is that the local moments begin to hybridize below T Ã , but their spectral weight is only gradually transferred to the heavy electron fluid.…”

Section: Antiferromagnetism and Relocalizationsupporting

confidence: 73%

Long range order and two-fluid behavior in heavy electron materials

Shirer

Shockley

Dioguardi

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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The heavy electron Kondo liquid is an emergent state of condensed matter that displays universal behavior independent of material details. Properties of the heavy electron liquid are best probed by NMR Knight shift measurements, which provide a direct measure of the behavior of the heavy electron liquid that emerges below the Kondo lattice coherence temperature as the lattice of local moments hybridizes with the background conduction electrons. Because the transfer of spectral weight between the localized and itinerant electronic degrees of freedom is gradual, the Kondo liquid typically coexists with the local moment component until the material orders at low temperatures. The two-fluid formula captures this behavior in a broad range of materials in the paramagnetic state. In order to investigate two-fluid behavior and the onset and physical origin of different long range ordered ground states in heavy electron materials, we have extended Knight shift measurements to URu 2 Si 2 , CeIrIn 5 , and CeRhIn 5 . In CeRhIn 5 we find that the antiferromagnetic order is preceded by a relocalization of the Kondo liquid, providing independent evidence for a local moment origin of antiferromagnetism. In URu 2 Si 2 the hidden order is shown to emerge directly from the Kondo liquid and so is not associated with local moment physics. Our results imply that the nature of the ground state is strongly coupled with the hybridization in the Kondo lattice in agreement with phase diagram proposed by Yang and Pines.nuclear magnetic resonance | heavy fermion | hyperfine couplings C ompetition between different energy scales gives rise to a rich spectrum of emergent ground states in strongly correlated electron materials. In the heavy fermion compounds, a lattice of nearly localized f electrons interacts with a sea of conduction electrons, and depending on the magnitude of this interaction different types of long-range order may develop at low temperatures (1). The Kondo lattice model strives to capture the essential physics of heavy fermion materials by considering the various magnetic interactions between the conduction electron spins, S c , and the local moment spins, S f (2). Different ground states can emerge depending on the relative strengths of the interaction, J, between S c and S f and the intersite interaction, J f f , between the S f spins (3, 4). Much of the physics of the phase diagram is driven by a quantum critical point, which separates long-range ordered ground states from those in which the local moments have fully hybridized with the conduction electrons to form itinerant states with large effective masses and large Fermi surfaces (5). In several materials quantum critical fluctuations give rise to anomalous non-Fermi liquid behavior in various bulk transport and thermodynamic quantities (6-8).In recent years, evidence has emerged that in the high temperature disordered phase the electronic degrees of freedom simultaneously exhibit both itinerant and localized behavior (9). Below a temperature T Ã that marks the onset...

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Section: Antiferromagnetism and Relocalizationsupporting

confidence: 73%

Long range order and two-fluid behavior in heavy electron materials

Shirer

Shockley

Dioguardi

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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“…In particular, the 41% reduction of the magnetic moment compared to 0.92 + expected from the crystal field ground state, together with the enhancement of the Ce magnetic form factor at large established by our measurements, suggest that even in the magnetically ordered state the magnetic moments are significantly Kondo screened in CeRhIn 5 . Similarly, sizable Kondo screening is also suggested by NMR measurements (5 K ~ 0.4 meV) [17], and by the large critical magnetic field ~50 T (~5 meV) required to saturate the AFM state with a low ‡ = 3.8 K (~0.3 meV) [45]. Current theory treats the magnetically ordered state in heavy fermion materials in such a way that the Kondo interaction is negligible compared to the exchange interaction, but our results suggest that new theories which effectively incorporate a sizable Kondo interaction, even in the magnetically ordered state, are urgently needed to make progress on the understanding of the spin Hamiltonian and the emergent properties of heavy fermion materials.…”

Section: Resultsmentioning

confidence: 53%

Low temperature magnetic structure of CeRhIn₅by neutron diffraction on absorption-optimized samples

Fobes

Bauer

Thompson

et al. 2017

J. Phys.: Condens. Matter

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Abstract. Two aspects of the ambient pressure magnetic structure of heavy fermion material CeRhIn 5 have remained under some debate since its discovery: whether the structure is indeed an incommensurate helix or a spin density wave, and what is the precise magnitude of the ordered magnetic moment. By using a single crystal sample optimized for hot neutrons to minimize neutron absorption by Rh and In, here we report an ordered moment of = 0.54(2) + . In addition, by using spherical neutron polarimetry measurements on a similar single crystal sample, we have confirmed the helical nature of the magnetic structure, and identified a single chiral domain. IntroductionThe Doniach phase diagram explores a competition in energy scales common to heavy fermion materials, between the Ruderman-Kittel-Kasuya-Yosida (RKKY) and Kondo interactions, which scale as ~. and ~0 1/3 , respectively, where J is the dimensionless Kondo coupling constant [1]. On one side of the phase diagram exists localized magnetism due to RKKY and on the other a totally Kondo-quenched paramagnetic state. Perhaps the most interesting scenarios are those in the middle of the phase diagram where the Kondo and RKKY energy scales are comparable. To find systems of this nature it is imperative to accurately measure these energy scales. CeRhIn 5 is one such system where these scales are believed to be competing.The temperature-pressure phase diagram of CeRhIn 5 is prototypical for heavy fermion materials; at ambient pressure, it displays incommensurate antiferromagnetic (AFM) order below T N = 3.8 K, and with increasing applied pressure T N is suppressed to a quantum critical point at P c = 2.25 GPa around which a broad dome of unconventional superconductivity emerges [2][3][4][5]. In detail, however, the properties of the AFM ground state in CeRhIn 5 deviate from prototypical behavior. Namely, the ground state magnetic order was reported to be helical, rather than spin-density-wave-type (SDW) by neutron measurements [2] and was later confirmed by 115 In NQR measurements [6,7]. Notably, the Ce magnetic moments were found to lie in the tetragonal ab-plane with the helix propagating along c [8]. Recent neutron spectroscopy measurements observed a small energy gap Δ = 0.25 meV in the spin wave spectra of the AFM state [9], but in the absence of magnetic anisotropies in the plane containing the spiraling spins a gapless Goldstone mode is expected for an incommensurate helical magnetic structure. Although an in-plane interaction invariant under the C 4 symmetry of the tetragonal structure may be possible, the gapless Goldstone mode is protected by translational symmetry of the magnetic helix along c. In principle, a sufficiently strong C 4 magnetic anisotropy (comparable to the exchange interactions along c), would distort the magnetic helix and break the associated translational symmetry, resulting in the formation of a spin gap. However, distortion of the helix would also lead to higher harmonic diffraction peaks, which have never been

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“…Interestingly, some of these properties, such as the concomitant observation of unconventional SC and heavy fermion (HF) behavior, seem to be favored in systems with tetragonal structure. Well known examples are the Ce-based heavy fermions superconductors CeM In 5 (M = Co, Rh, Ir), Ce 2 M In 8 (M = Co, Rh, Pd), CePt 2 In 7 (M = Co, Rh, Ir, Pd) [3][4][5][6][7] and CeCu 2 Si 2 [8,9].…”

Section: Introductionmentioning

confidence: 99%

Physical properties and magnetic structure of the intermetallicCeCuBi2compound

et al. 2014

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In this work, we combine magnetization, pressure dependent electrical resistivity, heat-capacity, 63 Cu Nuclear Magnetic Resonance (NMR) and X-ray resonant magnetic scattering experiments to investigate the physical properties of the intermetallic CeCuBi2 compound. Our single crystals show an antiferromagnetic ordering at TN ≃ 16 K and the magnetic properties indicate that this compound is an Ising antiferromagnet. In particular, the low temperature magnetization data revealed a spin-flop transition at T = 5 K when magnetic fields of about 5.5 T are applied along the c-axis. Moreover, the X-ray magnetic diffraction data below TN revealed a commensurate antiferromagnetic structure with propagation wavevector (0 0 1 2 ) with the Ce 3+ moments oriented along the c-axis. Furthermore, our heat capacity, pressure dependent resistivity, and temperature dependent 63 Cu NMR data suggest that CeCuBi2 exhibits a weak heavy fermion behavior with strongly localized Ce 3+ 4f electrons. We thus discuss a scenario in which both the anisotropic magnetic interactions between the Ce 3+ ions and the tetragonal crystalline electric field effects are taking into account in CeCuBi2.

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Low-Frequency Spin Dynamics in theCeMIn5Materials

Cited by 54 publications

References 29 publications

Long range order and two-fluid behavior in heavy electron materials

Long range order and two-fluid behavior in heavy electron materials

Low temperature magnetic structure of CeRhIn₅by neutron diffraction on absorption-optimized samples

Physical properties and magnetic structure of the intermetallicCeCuBi2compound

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Low-Frequency Spin Dynamics in theCeMIn5Materials

Cited by 54 publications

References 29 publications

Long range order and two-fluid behavior in heavy electron materials

Long range order and two-fluid behavior in heavy electron materials

Low temperature magnetic structure of CeRhIn5by neutron diffraction on absorption-optimized samples

Physical properties and magnetic structure of the intermetallicCeCuBi2compound

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Product

Resources

About

Low temperature magnetic structure of CeRhIn₅by neutron diffraction on absorption-optimized samples