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Bachmann MD, Ferguson GM, Theuss F, Meng T, Putzke C, Helm T, Shirer KR, Li YS, Modic KA, Nicklas M, König M, Low D, Ghosh S, Mackenzie AP, Arnold F, Hassinger E, McDonald RD, Winter LE, Bauer ED, Ronning F, Ramshaw BJ, Nowack KC, Moll PJW. Spatial control of heavy-fermion superconductivity in CeIrIn5. Science 2019; 366:221-226. [DOI: 10.1126/science.aao6640] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 09/20/2018] [Accepted: 09/12/2019] [Indexed: 11/02/2022]
Abstract
Although crystals of strongly correlated metals exhibit a diverse set of electronic ground states, few approaches exist for spatially modulating their properties. In this study, we demonstrate disorder-free control, on the micrometer scale, over the superconducting state in samples of the heavy-fermion superconductor CeIrIn5. We pattern crystals by focused ion beam milling to tailor the boundary conditions for the elastic deformation upon thermal contraction during cooling. The resulting nonuniform strain fields induce complex patterns of superconductivity, owing to the strong dependence of the transition temperature on the strength and direction of strain. These results showcase a generic approach to manipulating electronic order on micrometer length scales in strongly correlated matter without compromising the cleanliness, stoichiometry, or mean free path.
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Affiliation(s)
- Maja D. Bachmann
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
- School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, UK
| | - G. M. Ferguson
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA
| | - Florian Theuss
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA
| | - Tobias Meng
- Institute for Theoretical Physics, Technical University Dresden, D-01062 Dresden, Germany
| | - Carsten Putzke
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
- Institute of Material Science and Engineering, École Polytechnique Fédéral de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Toni Helm
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - K. R. Shirer
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - You-Sheng Li
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
- School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, UK
| | - K. A. Modic
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - Michael Nicklas
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - Markus König
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - D. Low
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA
| | - Sayak Ghosh
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA
| | - Andrew P. Mackenzie
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
- School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, UK
| | - Frank Arnold
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - Elena Hassinger
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
- Physik-Department, Technische Universität München, Garching, D-85748 Germany
| | | | | | - Eric D. Bauer
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Filip Ronning
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - B. J. Ramshaw
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA
| | - Katja C. Nowack
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853, USA
| | - Philip J. W. Moll
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
- Institute of Material Science and Engineering, École Polytechnique Fédéral de Lausanne (EPFL), 1015 Lausanne, Switzerland
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Sakakibara T, Kittaka S, Machida K. Angle-resolved heat capacity of heavy fermion superconductors. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:094002. [PMID: 27482621 DOI: 10.1088/0034-4885/79/9/094002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Owing to a strong Coulomb repulsion, heavy electron superconductors mostly have anisotropic gap functions which have nodes for certain directions in the momentum space. Since the nodal structure is closely related to the pairing mechanism, its experimental determination is of primary importance. This article discusses the experimental methods of the gap determination by bulk heat capacity measurements in a rotating magnetic field. The basic idea is based on the fact that the quasiparticle density of states in the vortex state of nodal superconductors is field and direction dependent. We present our recent experimental results of the field-orientation dependence of the heat capacity in heavy fermion superconductors CeTIn5 (T = Co, Ir), UPt3, CeCu2Si2, and UBe13 and discuss their gap structures.
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Affiliation(s)
- Toshiro Sakakibara
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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Ishii T, Toda R, Hanaoka Y, Tokiwa Y, Shimozawa M, Kasahara Y, Endo R, Terashima T, Nevidomskyy AH, Shibauchi T, Matsuda Y. Tuning the Magnetic Quantum Criticality of Artificial Kondo Superlattices CeRhIn_{5}/YbRhIn_{5}. PHYSICAL REVIEW LETTERS 2016; 116:206401. [PMID: 27258878 DOI: 10.1103/physrevlett.116.206401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Indexed: 06/05/2023]
Abstract
The effects of reduced dimensions and the interfaces on antiferromagnetic quantum criticality are studied in epitaxial Kondo superlattices, with alternating n layers of heavy-fermion antiferromagnet CeRhIn_{5} and seven layers of normal metal YbRhIn_{5}. As n is reduced, the Kondo coherence temperature is suppressed due to the reduction of effective Kondo screening. The Néel temperature is gradually suppressed as n decreases and the quasiparticle mass is strongly enhanced, implying dimensional control toward a quantum critical point. Magnetotransport measurements reveal that a quantum critical point is reached for the n=3 superlattice by applying small magnetic fields. Remarkably, the anisotropy of the quantum critical field is opposite to the expectations from the magnetic susceptibility in bulk CeRhIn_{5}, suggesting that the Rashba spin-orbit interaction arising from the inversion symmetry breaking at the interface plays a key role for tuning the quantum criticality in the two-dimensional Kondo lattice.
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Affiliation(s)
- T Ishii
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - R Toda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Y Hanaoka
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Y Tokiwa
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
- Research Center for Low Temperature and Materials Science, Kyoto University, Kyoto 606-8501, Japan
| | - M Shimozawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Y Kasahara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - R Endo
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Terashima
- Research Center for Low Temperature and Materials Science, Kyoto University, Kyoto 606-8501, Japan
| | - A H Nevidomskyy
- Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, USA
| | - T Shibauchi
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - Y Matsuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
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Yashima M, Tagami N, Taniguchi S, Unemori T, Uematsu K, Mukuda H, Kitaoka Y, Ota Y, Honda F, Settai R, Onuki Y. Possibility of valence-fluctuatsion-mediated superconductivity in Cd-doped CeIrIn(5) probed by In NQR. PHYSICAL REVIEW LETTERS 2012; 109:117001. [PMID: 23005666 DOI: 10.1103/physrevlett.109.117001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 06/12/2012] [Indexed: 06/01/2023]
Abstract
We report on a pressure-induced evolution of exotic superconductivity and spin correlations in CeIr(In(1-x)Cd(x))(5) by means of in-nuclear-quadrupole-resonance (NQR) studies. Measurements of an NQR spectrum and nuclear-spin-lattice-relaxation rate 1/T(1) have revealed that antiferromagnetism induced by Cd doping emerges locally around Cd dopants, but superconductivity is suddenly induced at T(c)=0.7 and 0.9 K at 2.34 and 2.75 GPa, respectively. The unique superconducting characteristics with a large fraction of the residual density of state at the Fermi level which increases with T(c) differ from those for anisotropic superconductivity mediated by antiferromagnetic correlations. By incorporating the pressure dependence of the NQR frequency pointing to the valence change of Ce, we suggest that unconventional superconductivity in the CeIr(In(1-x)Cd(x))(5) system may be mediated by valence fluctuations.
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Affiliation(s)
- M Yashima
- Department of Materials Engineering Science, Osaka University, Osaka 560-8531, Japan
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Ronning F, Zhu JX, Das T, Graf MJ, Albers RC, Rhee HB, Pickett WE. Superconducting gap structure of the 115s revisited. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:294206. [PMID: 22773378 DOI: 10.1088/0953-8984/24/29/294206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Density functional theory calculations of the electronic structure of Ce- and Pu-based heavy fermion superconductors in the so-called 115 family are performed. The gap equation is used to consider which superconducting order parameters are most favorable assuming a pairing interaction that is peaked at (π, π, qz)—the wavevector for the antiferromagnetic ordering found in close proximity. In addition to the commonly accepted dx2−y2 order parameter, there is evidence that an extended s-wave order parameter with nodes is also plausible. We discuss whether these results are consistent with current observations and possible measurements that could help distinguish between these scenarios.
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Affiliation(s)
- F Ronning
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
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Lu X, Lee H, Park T, Ronning F, Bauer ED, Thompson JD. Heat-capacity measurements of energy-gap nodes of the heavy-fermion superconductor CeIrIn5 deep inside the pressure-dependent dome structure of its superconducting phase diagram. PHYSICAL REVIEW LETTERS 2012; 108:027001. [PMID: 22324705 DOI: 10.1103/physrevlett.108.027001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Indexed: 05/31/2023]
Abstract
We use heat-capacity measurements as a function of field rotation to identify the nodal gap structure of CeIrIn(5) at pressures to 2.05 GPa, deep inside its superconducting dome. A fourfold oscillation in the heat capacity at 0.3 K is observed for all pressures, but with its sign reversed between 1.50 and 0.90 GPa. On the basis of recent theoretical models for the field-angle-dependent specific heat, all data, including the sign reversal, imply a d(x(2)-y(2)) order parameter with nodes along [110], which constrains theoretical models of the pairing mechanism in CeIrIn(5).
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Affiliation(s)
- Xin Lu
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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