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Stock C, Rodriguez-Rivera JA, Schmalzl K, Demmel F, Singh DK, Ronning F, Thompson JD, Bauer ED. From Ising Resonant Fluctuations to Static Uniaxial Order in Antiferromagnetic and Weakly Superconducting CeCo(In_{1-x}Hg_{x})_{5}(x=0.01). Phys Rev Lett 2018; 121:037003. [PMID: 30085774 DOI: 10.1103/physrevlett.121.037003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Indexed: 06/08/2023]
Abstract
CeCo(In_{0.990}Hg_{0.010})_{5} is a charge doped variant of the d-wave CoCoIn_{5} superconductor with coexistent antiferromagnetic and superconducting transitions occurring at T_{N}=3.4 and T_{c}=1.4 K, respectively. We use neutron diffraction and spectroscopy to show that the magnetic resonant fluctuations present in the parent superconducting phase are replaced by collinear c-axis magnetic order with three-dimensional Ising critical fluctuations. No low-energy transverse spin fluctuations are observable in this doping-induced antiferromagnetic phase and the dynamic resonant spectral weight predominately shifts to the elastic channel. Static (τ>0.2 ns) collinear Ising order is proximate to superconductivity in CeCoIn_{5} and is stabilized through hole doping with Hg.
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Affiliation(s)
- C Stock
- School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - J A Rodriguez-Rivera
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
- Department of Materials Science, University of Maryland, College Park, Maryland 20742, USA
| | - K Schmalzl
- Forschungszentrum Juelich GmbH, Juelich Centre for Neutron Science at ILL, 71 avenue des Martyrs, 38000 Grenoble, France
| | - F Demmel
- ISIS Facility, Rutherford Appleton Labs, Chilton, Didcot OX11 0QX, United Kingdom
| | - D K Singh
- Department of Physics and Astronomy, University of Missouri, Missouri 65211, USA
| | - F Ronning
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J D Thompson
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E D Bauer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Abstract
Nuclear magnetic resonance has emerged as a vital tool to explore the fundamental physics of Kondo lattice systems. Because nuclear spins experience two different hyperfine couplings to the itinerant conduction electrons and to the local f moments, the Knight shift can probe multiple types of spin correlations that are not accessible via other techniques. The Knight shift provides direct information about the onset of heavy electron coherence and the emergence of the heavy electron fluid.
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Affiliation(s)
- Nicholas J Curro
- Department of Physics, University of California, Davis, CA 95616, USA
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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.
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Kitagawa K, Katayama N, Gotou H, Yagi T, Ohgushi K, Matsumoto T, Uwatoko Y, Takigawa M. Spontaneous formation of a superconducting and antiferromagnetic hybrid state in SrFe2As2 under high pressure. Phys Rev Lett 2009; 103:257002. [PMID: 20366276 DOI: 10.1103/physrevlett.103.257002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 11/03/2009] [Indexed: 05/29/2023]
Abstract
We report a novel superconducting (SC) and antiferromagnetic (AF) hybrid state in SrFe(2)As(2) revealed by (75)As nuclear magnetic resonance (NMR) experiments on a single crystal under highly hydrostatic pressure up to 7 GPa. The NMR spectra at 5.4 GPa indicate simultaneous development of the SC and AF orders below 30 K. The nuclear spin-lattice relaxation rate in the SC domains shows a substantial residual density of states, suggesting proximity effects due to the spontaneous formation of a nanoscale SC-AF hybrid structure. This entangled behavior is a remarkable example of a self-organized heterogeneous structure in a clean system.
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Affiliation(s)
- K Kitagawa
- Institute for Solid State Physics, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
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Park T, Bauer ED, Thompson JD. Probing the nodal gap in the pressure-induced heavy fermion superconductor CeRhIn5. Phys Rev Lett 2008; 101:177002. [PMID: 18999775 DOI: 10.1103/physrevlett.101.177002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Indexed: 05/27/2023]
Abstract
We report field-orientation specific heat studies of the pressure-induced heavy-fermion superconductor CeRhIn5. These experiments provide the momentum-dependent superconducting gap function for the first time in any pressure-induced superconductor. In the coexisting phase of superconductivity and antiferromagnetism, field rotation within the Ce-In plane reveals fourfold modulation in the density of states, which favors a d-wave order parameter and constrains a theory of the interplay between superconductivity and magnetism.
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Affiliation(s)
- Tuson Park
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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Goh SK, Paglione J, Sutherland M, O'Farrell ECT, Bergemann C, Sayles TA, Maple MB. Fermi-surface reconstruction in CeRh1-xCoxIn5. Phys Rev Lett 2008; 101:056402. [PMID: 18764411 DOI: 10.1103/physrevlett.101.056402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Indexed: 05/26/2023]
Abstract
The evolution of the Fermi surface of CeRh(1-x)CoxIn5 was studied as a function of Co concentration x via measurements of the de Haas-van Alphen effect. By measuring the angular dependence of quantum oscillation frequencies, we identify a Fermi-surface sheet with f-electron character which undergoes an abrupt change in topology as x is varied. Surprisingly, this reconstruction does not occur at the quantum critical concentration x(c), where antiferromagnetism is suppressed to T=0. Instead we establish that this sudden change occurs well below x(c), at the concentration x approximately 0.4, where long-range magnetic order alters its character and superconductivity appears. Across all concentrations, the cyclotron effective mass of this sheet does not diverge, suggesting that critical behavior is not exhibited equally on all parts of the Fermi surface.
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Affiliation(s)
- Swee K Goh
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, United Kingdom
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Urbano RR, Young BL, Curro NJ, Thompson JD, Pham LD, Fisk Z. Interacting antiferromagnetic droplets in quantum critical CeCoIn5. Phys Rev Lett 2007; 99:146402. [PMID: 17930691 DOI: 10.1103/physrevlett.99.146402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Indexed: 05/25/2023]
Abstract
The heavy fermion superconductor CeCoIn5 can be tuned between superconducting and antiferromagnetic ground states by hole doping with Cd. Nuclear magnetic resonance data indicate that these two orders coexist microscopically with an ordered moment approximately 0.7 microB. As the ground state evolves, there is no change in the low-frequency spin dynamics in the disordered state. These results suggest that the magnetism emerges locally in the vicinity of the Cd dopants.
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Affiliation(s)
- R R Urbano
- Condensed Matter and Thermal Physics, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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Tanaka Y, Golubov AA, Kashiwaya S, Ueda M. Anomalous Josephson effect between even- and odd-frequency superconductors. Phys Rev Lett 2007; 99:037005. [PMID: 17678318 DOI: 10.1103/physrevlett.99.037005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2006] [Revised: 12/27/2006] [Indexed: 05/16/2023]
Abstract
We demonstrate that, contrary to standard wisdom, the lowest-order Josephson coupling is possible between odd- and even-frequency superconductors. The origin of this effect is the induced odd- (even-)frequency pairing component at the interface of bulk even- (odd-)frequency superconductors. The resulting current-phase relation is found to be proportional to cosphi, where phi is the macroscopic phase difference between the two superconductors.
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Affiliation(s)
- Yukio Tanaka
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
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9
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Abstract
The magnetically ordered ground state of CeRhIn(5) at ambient pressure and zero magnetic field is an incommensurate helicoidal phase with the propagation vector k = (1/2,1/2,0.298) and the magnetic moment in the basal plane of the tetragonal structure. We determined by neutron diffraction the two different magnetically ordered phases of CeRhIn(5) evidenced by bulk measurements under applied magnetic field in the basal plane. The low temperature high magnetic phase corresponds to a commensurate sine-wave structure of the magnetization with k = (1/2,1/2,1/4). At high temperature, the phase is incommensurate with k = (1/2,1/2,0.298) and a possible small ellipticity. The propagation vector of this phase is the same as that of the zero-field structure.
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Affiliation(s)
- S Raymond
- CEA-Grenoble, DRFMC, SPSMS, 38054 Grenoble Cedex 9, France
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Tanaka Y, Golubov AA. Theory of the proximity effect in junctions with unconventional superconductors. Phys Rev Lett 2007; 98:037003. [PMID: 17358718 DOI: 10.1103/physrevlett.98.037003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Indexed: 05/14/2023]
Abstract
We present a general theory of the proximity effect in junctions between diffusive normal metals (DN) and superconductors. Various possible symmetry classes in a superconductor are considered: even-frequency spin-singlet even-parity (ESE) state, even-frequency spin-triplet odd-parity state, odd-frequency spin-triplet even-parity (OTE) state and odd-frequency spin-singlet odd-parity state. It is shown that the pair amplitude in a DN belongs, respectively, to an ESE, OTE, OTE, and ESE pairing state since only the even-parity s-wave pairing is possible due to the impurity scattering.
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Affiliation(s)
- Y Tanaka
- Department of Applied Physics, Nagoya University, Nagoya, 464-8603, Japan
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11
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Chen GF, Matsubayashi K, Ban S, Deguchi K, Sato NK. Competitive coexistence of superconductivity with antiferromagnetism in CeRhIn5. Phys Rev Lett 2006; 97:017005. [PMID: 16907401 DOI: 10.1103/physrevlett.97.017005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2005] [Indexed: 05/11/2023]
Abstract
We carried out ac magnetic susceptibility measurements under pressures P on the heavy fermion antiferromagnet CeRhIn5. We report bulk superconductivity (SC) at ambient pressure with a transition temperature Tc approximately or equal to 90 mK. The degraded SC in a powdered or polished sample was restored by annealing, showing that the SC state is sensitive to inhomogeneity. In a coexistence region of the SC with antiferromagnetism (AF), we find that Tc(P)(n)TN(P)(1-n) = const where TN indicates a Néel temperature and n denotes a ratio of electronic specific heat coefficients below and above TN, indicating the competition of the SC and the AF for states at the Fermi surface.
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Affiliation(s)
- G F Chen
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
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12
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Kawasaki S, Yashima M, Mugino Y, Mukuda H, Kitaoka Y, Shishido H, Onuki Y. Enhancing the superconducting transition temperature of CeRh 1-x IrxIn5 due to the strong-coupling effects of antiferromagnetic spin fluctuations: an 115In nuclear quadrupole resonance study. Phys Rev Lett 2006; 96:147001. [PMID: 16712110 DOI: 10.1103/physrevlett.96.147001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Indexed: 05/09/2023]
Abstract
We report on systematic evolutions of antiferromagnetic (AFM) spin fluctuations and unconventional superconductivity (SC) in heavy-fermion (HF) compounds CeRh(1-x)Ir(x)In(5) via an (115)In nuclear-quadrupole-resonance experiment. The nuclear spin-lattice relaxation rate 1/T(1) has revealed the marked development of AFM spin fluctuations as approaching an AFM ordered state. Concomitantly, the superconducting transition temperature T(c) and the energy gap Delta0 increase drastically from T(c)= 0.4K and 2Delta0/k(B)T(c)=5 in CeIrIn(5) up to T(c) =1.2K and 2Delta0/k(B)T(c) =8.3 in CeRh(0.3)Ir(0.7)In5 , respectively. The present work suggests that the AFM spin fluctuations in close proximity to the AFM quantum critical point are indeed responsible for the strong-coupling unconventional SC in HF compounds.
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Affiliation(s)
- Shinji Kawasaki
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
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13
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Mukuda H, Abe M, Araki Y, Kitaoka Y, Tokiwa K, Watanabe T, Iyo A, Kito H, Tanaka Y. Uniform mixing of high-Tc superconductivity and antiferromagnetism on a single CuO2 plane of a Hg-based five-layered cuprate. Phys Rev Lett 2006; 96:087001. [PMID: 16606215 DOI: 10.1103/physrevlett.96.087001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Indexed: 05/08/2023]
Abstract
We report a site selective Cu-NMR study on underdoped Hg-based five-layered high-Tc cuprate HgBa2Ca4CU5O(12+delta) with a Tc = 72 K. Antiferromagnetism (AFM) has been found to take place at T(N) = 290 K, exhibiting a large antiferromagnetic moment of 0.67-0.69 microB at three inner planes (IP). This value is comparable to the values reported for nondoped cuprates, suggesting that the IP may be in a nearly nondoped regime. Most surprisingly, the AFM order is also detected with M(AFM)(OP) = 0.1 microB even at two outer planes (OP) that are responsible for the onset of superconductivity (SC). The high-Tc SC at Tc = 72 K can uniformly coexist on a microscopic level with the AFM at OP's. This is the first microscopic evidence for the uniform mixed phase of AFM and SC on a single CuO2 plane in a simple environment without any vortex lattice and/or stripe order.
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Affiliation(s)
- H Mukuda
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
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Young DP, Moldovan M, Wu XS, Adams PW, Chan JY. Low-temperature susceptibility of the noncentrosymmetric superconductor CePt3Si. Phys Rev Lett 2005; 94:107001. [PMID: 15783505 DOI: 10.1103/physrevlett.94.107001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Revised: 11/22/2004] [Indexed: 05/24/2023]
Abstract
We report ac susceptibility measurements of polycrystalline CePt(3)Si down to 60 mK and in applied fields up to 9 T. In a zero applied field, a full Meissner state emerges at temperatures T/T(c) < 0.3, where T(c) = 0.65 K is the onset transition temperature. Though transport measurements show a relatively high upper critical field B(c2) approximately 4-5 T, the low-temperature susceptibility chi(') is quite fragile to the applied field, with chi(') diminishing rapidly in fields of a few kG. Interestingly, the field dependence of chi(') is well described by the power law 4pichi(') + 1 = (B/B(c))(1/2), where B(c) is the field at which the onset of resistance is observed in transport measurements.
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Affiliation(s)
- D P Young
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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Fujimoto T, Zheng GQ, Kitaoka Y, Meng RL, Cmaidalka J, Chu CW. Unconventional superconductivity and electron correlations in the cobalt oxyhydrate Na0.35CoO2.yH2O from nuclear quadrupole resonance. Phys Rev Lett 2004; 92:047004. [PMID: 14995398 DOI: 10.1103/physrevlett.92.047004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2003] [Indexed: 05/24/2023]
Abstract
We report a careful 59Co nuclear quadrupolar resonance measurement on the recently discovered cobalt oxyhydrate Na0.35CoO2.yH(2)O superconductor from T=40 K down to 0.2 K. We find that in the normal state the spin-lattice relaxation rate 1/T(1) follows a Curie-Weiss type temperature (T) variation, 1/T(1)T=C/(T-theta), with theta=-42 K, suggesting two-dimensional antiferromagnetic spin correlations. Below T(c)=3.9 K, 1/T(1) decreases with no coherence peak and follows a T(n) dependence with n approximately 2.2 down to approximately 2.0 K but crosses over to a 1/T(1) proportional to T variation below T=1.4 K, which suggests non-s-wave superconductivity. The data in the superconducting state are most consistent with the existence of line nodes in the gap function.
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Affiliation(s)
- Tatsuya Fujimoto
- Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
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