1
|
Piva MM, Ajeesh MO, Christovam DS, Dos Reis RD, Jesus CBR, Rosa PFS, Adriano C, Urbano RR, Nicklas M, Pagliuso PG. High-pressure studies on heavy-fermion antiferromagnet CeCuBi 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:375601. [PMID: 30074484 DOI: 10.1088/1361-648x/aad7d8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report in-plane electrical resistivity studies of CeCuBi2 and LaCuBi2 single crystals under applied pressure. At ambient pressure, CeCuBi2 is a c-axis Ising antiferromagnet with a transition temperature [Formula: see text] K. In a magnetic field applied along the c-axis at [Formula: see text] K a spin-flop transition takes place [Formula: see text] T. Applying pressure on CeCuBi2 suppresses T N at a slow rate. [Formula: see text] extrapolates to zero temperature at [Formula: see text] GPa. The critical field of the spin-flop transition [Formula: see text] displays a maximum of 6.8 T at [Formula: see text] GPa. At low temperatures, a zero-resistance superconducting state emerges upon the application of external pressure having a maximum T c of 7 K at 2.6 GPa in CeCuBi2. High-pressure electrical-resistivity experiments on the non-magnetic reference compound LaCuBi2 reveal also a zero resistance state with similar critical temperatures in the same pressure range as CeCuBi2. The great similarity between the superconducting properties of both materials and elemental Bi suggests a common origin of the superconductivity. We discuss that the appearance of this zero resistance state superconductivity may be related to the Bi layers present in the crystalline structure of both compounds and, therefore, could be intrinsic to CeCuBi2 and LaCuBi2, however further experiments under pressure are necessary to clarify this issue.
Collapse
Affiliation(s)
- M M Piva
- Instituto de Física 'Gleb Wataghin', UNICAMP, 13083-859, Campinas, SP, Brazil. Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Fobes DM, Bauer ED, Thompson JD, Sazonov A, Hutanu V, Zhang S, Ronning F, Janoschek M. Low temperature magnetic structure of CeRhIn 5 by neutron diffraction on absorption-optimized samples. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:17LT01. [PMID: 28349895 DOI: 10.1088/1361-648x/aa6696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Two aspects of the ambient pressure magnetic structure of heavy fermion material CeRhIn5 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 [Formula: see text]. 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.
Collapse
Affiliation(s)
- D M Fobes
- MPA-CMMS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States of America
| | | | | | | | | | | | | | | |
Collapse
|
3
|
Yang YF. Two-fluid model for heavy electron physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:074501. [PMID: 27214153 DOI: 10.1088/0034-4885/79/7/074501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The two-fluid model is a phenomenological description of the gradual change of the itinerant and local characters of f-electrons with temperature and other tuning parameters and has been quite successful in explaining many unusual and puzzling experimental observations in heavy electron materials. We review some of these results and discuss possible implications of the two-fluid model in understanding the microscopic origin of heavy electron physics.
Collapse
Affiliation(s)
- Yi-Feng Yang
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China. Collaborative Innovation Center of Quantum Matter, Beijing 100190, People's Republic of China
| |
Collapse
|
4
|
Das P, Lin SZ, Ghimire NJ, Huang K, Ronning F, Bauer ED, Thompson JD, Batista CD, Ehlers G, Janoschek M. Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn₅. PHYSICAL REVIEW LETTERS 2014; 113:246403. [PMID: 25541784 DOI: 10.1103/physrevlett.113.246403] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Indexed: 06/04/2023]
Abstract
We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn₅. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J₁-J₂ model that also naturally explains the magnetic spin-spiral ground state of CeRhIn₅ and yields a dominant in-plane nearest-neighbor magnetic exchange constant J₀=0.74(3) meV. Our results pave the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn₅ (T=Co, Rh, Ir) class of heavy-fermion materials.
Collapse
Affiliation(s)
- Pinaki Das
- Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S-Z Lin
- T-4, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - N J Ghimire
- Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K Huang
- Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA and Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
| | - F Ronning
- Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E D Bauer
- Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J D Thompson
- Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C D Batista
- T-4, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - G Ehlers
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6475, USA
| | - M Janoschek
- Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| |
Collapse
|
5
|
Tokiwa Y, Bauer ED, Gegenwart P. Zero-field quantum critical point in CeCoIn5. PHYSICAL REVIEW LETTERS 2013; 111:107003. [PMID: 25166697 DOI: 10.1103/physrevlett.111.107003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/02/2013] [Indexed: 06/03/2023]
Abstract
Quantum criticality in the normal and superconducting states of the heavy-fermion metal CeCoIn5 is studied by measurements of the magnetic Grüneisen ratio ΓH and specific heat in different field orientations and temperatures down to 50 mK. A universal temperature over magnetic field scaling of ΓH in the normal state indicates a hidden quantum critical point at zero field. Within the superconducting state, the quasiparticle entropy at constant temperature increases upon reducing the field towards zero, providing additional evidence for zero-field quantum criticality.
Collapse
Affiliation(s)
- Y Tokiwa
- I. Physikalisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - E D Bauer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - P Gegenwart
- I. Physikalisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| |
Collapse
|
6
|
Abstract
We obtain the conditions necessary for the emergence of various low-temperature ordered states (local-moment antiferromagnetism, unconventional superconductivity, quantum criticality, and Landau Fermi liquid behavior) in Kondo lattice materials by extending the two-fluid phenomenological theory of heavy-electron behavior to incorporate the concept of hybridization effectiveness. We use this expanded framework to present a new phase diagram and consistent physical explanation and quantitative description of measured emergent behaviors such as the pressure variation of the onset of local-moment antiferromagnetic ordering at T(N), the magnitude of the ordered moment, the growth of superconductivity within that ordered state, the location of a quantum critical point, and of a delocalization line in the pressure/temperature phase diagram at which local moments have disappeared and the heavy-electron Fermi surface has grown to its maximum size. We apply our model to CeRhIn(5) and a number of other heavy-electron materials and find good agreement with experiment.
Collapse
|
7
|
Long range order and two-fluid behavior in heavy electron materials. Proc Natl Acad Sci U S A 2012; 109:E3067-73. [PMID: 23010926 DOI: 10.1073/pnas.1209609109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
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.
Collapse
|
8
|
Smith MF, McKenzie RH. Apparent violation of the Wiedemann-Franz law near a magnetic field tuned metal-antiferromagnetic quantum critical point. PHYSICAL REVIEW LETTERS 2008; 101:266403. [PMID: 19437656 DOI: 10.1103/physrevlett.101.266403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The temperature dependences of the interlayer electrical and thermal resistivity in a layered metal are calculated for Fermi liquid quasiparticles which are scattered inelastically by two-dimensional antiferromagnetic spin fluctuations. Both resistivities have a linear temperature dependence over a broad temperature range. Extrapolations to zero temperature made from this linear-T range give values that appear to violate the Wiedemann-Franz law. However, below a low-temperature scale, which becomes small close to the critical point, a recovery of this law occurs. Our results describe recent measurements on CeCoIn5 near a magnetic field-induced quantum phase transition. Hence, the experiments do not necessarily imply a non-Fermi liquid ground state.
Collapse
Affiliation(s)
- M F Smith
- University of Queensland, Department of Physics, 4072 Brisbane, Queensland, Australia.
| | | |
Collapse
|
9
|
Yang YF, Pines D. Universal behavior in heavy-electron materials. PHYSICAL REVIEW LETTERS 2008; 100:096404. [PMID: 18352734 DOI: 10.1103/physrevlett.100.096404] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Indexed: 05/26/2023]
Abstract
We present our finding that an especially simple scaling expression describes the formation of a new state of quantum matter, the Kondo Fermi liquid (KL) in heavy-electron materials. Emerging at T* as a result of the collective coherent hybridization of localized f electrons and conduction electrons, the KL possesses a non-Landau density of states varying as (1-T/T*)3/2[1+ln(T*/T)]. We show that four independent experimental probes verify this scaling behavior and that for CeIrIn5 the KL state density is in excellent agreement with the recent microscopic calculations.
Collapse
Affiliation(s)
- Yi-feng Yang
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | | |
Collapse
|
10
|
Mitrović VF, Horvatić M, Berthier C, Knebel G, Lapertot G, Flouquet J. Observation of spin susceptibility enhancement in the possible Fulde-Ferrell-Larkin-Ovchinnikov state of CeCoIn(5). PHYSICAL REVIEW LETTERS 2006; 97:117002. [PMID: 17025921 DOI: 10.1103/physrevlett.97.117002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Indexed: 05/12/2023]
Abstract
We report (115)In nuclear magnetic resonance measurements of the heavy-fermion superconductor CeCoIn(5) in the vicinity of the superconducting critical field H(c2) for a magnetic field applied perpendicular to the ĉ axis. A possible inhomogeneous superconducting state, the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, is stabilized in this part of the phase diagram. In an 11 T applied magnetic field, we observe clear signatures of the two phase transitions: the higher temperature one to the homogeneous superconducting state and the lower temperature phase transition to a FFLO state. We find that the spin susceptibility in the putative FFLO state is significantly enhanced as compared to the value in a homogeneous superconducting state. The implications of this finding for the nature of the low temperature phase are discussed.
Collapse
Affiliation(s)
- V F Mitrović
- Department of Physics, Brown University, Providence, Rhode Island 02912, USA
| | | | | | | | | | | |
Collapse
|
11
|
Llobet A, Christianson AD, Bao W, Gardner JS, Swainson IP, Lynn JW, Mignot JM, Prokes K, Pagliuso PG, Moreno NO, Sarrao JL, Thompson JD, Lacerda AH. Novel coexistence of superconductivity with two distinct magnetic orders. PHYSICAL REVIEW LETTERS 2005; 95:217002. [PMID: 16384171 DOI: 10.1103/physrevlett.95.217002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Indexed: 05/05/2023]
Abstract
The heavy fermion system exhibits properties that range from an incommensurate antiferromagnet for small to an exotic superconductor on the Ir-rich end of the phase diagram. At intermediate where antiferromagnetism coexists with superconductivity, two types of magnetic order are observed: the incommensurate one of and a new, commensurate antiferromagnetism that orders separately. The coexistence of -electron superconductivity with two distinct -electron magnetic orders is unique among unconventional superconductors, adding a new variety to the usual coexistence found in magnetic superconductors.
Collapse
Affiliation(s)
- A Llobet
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Nakatsuji S, Pines D, Fisk Z. Two fluid description of the Kondo lattice. PHYSICAL REVIEW LETTERS 2004; 92:016401. [PMID: 14754005 DOI: 10.1103/physrevlett.92.016401] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2003] [Indexed: 05/24/2023]
Abstract
We present a two-fluid description of the Kondo lattice that is based on an analysis of CeCoIn5 at various levels of dilution with La. We show that thermal and transport measurements provide evidence for the survival of the Kondo impurity component in the lattice as T-->0 K, and that the evolution of the low temperature properties of the Kondo lattice can be viewed as the partial condensation of the lattice of Kondo centers into a heavy fermion fluid. The resulting two-fluid model is shown to be applicable to the general problem of the ground state of the Kondo lattice.
Collapse
Affiliation(s)
- Satoru Nakatsuji
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | | | | |
Collapse
|