1
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Posey VA, Turkel S, Rezaee M, Devarakonda A, Kundu AK, Ong CS, Thinel M, Chica DG, Vitalone RA, Jing R, Xu S, Needell DR, Meirzadeh E, Feuer ML, Jindal A, Cui X, Valla T, Thunström P, Yilmaz T, Vescovo E, Graf D, Zhu X, Scheie A, May AF, Eriksson O, Basov DN, Dean CR, Rubio A, Kim P, Ziebel ME, Millis AJ, Pasupathy AN, Roy X. Two-dimensional heavy fermions in the van der Waals metal CeSiI. Nature 2024; 625:483-488. [PMID: 38233620 DOI: 10.1038/s41586-023-06868-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 11/14/2023] [Indexed: 01/19/2024]
Abstract
Heavy-fermion metals are prototype systems for observing emergent quantum phases driven by electronic interactions1-6. A long-standing aspiration is the dimensional reduction of these materials to exert control over their quantum phases7-11, which remains a significant challenge because traditional intermetallic heavy-fermion compounds have three-dimensional atomic and electronic structures. Here we report comprehensive thermodynamic and spectroscopic evidence of an antiferromagnetically ordered heavy-fermion ground state in CeSiI, an intermetallic comprising two-dimensional (2D) metallic sheets held together by weak interlayer van der Waals (vdW) interactions. Owing to its vdW nature, CeSiI has a quasi-2D electronic structure, and we can control its physical dimension through exfoliation. The emergence of coherent hybridization of f and conduction electrons at low temperature is supported by the temperature evolution of angle-resolved photoemission and scanning tunnelling spectra near the Fermi level and by heat capacity measurements. Electrical transport measurements on few-layer flakes reveal heavy-fermion behaviour and magnetic order down to the ultra-thin regime. Our work establishes CeSiI and related materials as a unique platform for studying dimensionally confined heavy fermions in bulk crystals and employing 2D device fabrication techniques and vdW heterostructures12 to manipulate the interplay between Kondo screening, magnetic order and proximity effects.
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Affiliation(s)
| | - Simon Turkel
- Physics Department, Columbia University, New York, NY, USA
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
| | - Mehdi Rezaee
- Physics Department, Harvard University, Cambridge, MA, USA
| | | | - Asish K Kundu
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
| | - Chin Shen Ong
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
| | - Morgan Thinel
- Chemistry Department, Columbia University, New York, NY, USA
- Physics Department, Columbia University, New York, NY, USA
| | - Daniel G Chica
- Chemistry Department, Columbia University, New York, NY, USA
| | | | - Ran Jing
- Physics Department, Columbia University, New York, NY, USA
| | - Suheng Xu
- Physics Department, Columbia University, New York, NY, USA
| | - David R Needell
- Chemistry Department, Columbia University, New York, NY, USA
| | - Elena Meirzadeh
- Chemistry Department, Columbia University, New York, NY, USA
| | | | - Apoorv Jindal
- Physics Department, Columbia University, New York, NY, USA
| | - Xiaomeng Cui
- Physics Department, Harvard University, Cambridge, MA, USA
| | - Tonica Valla
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA
- Donostia International Physics Center (DIPC), Donostia-San Sebastián, Spain
| | - Patrik Thunström
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
| | - Turgut Yilmaz
- National Synchrotron Light Source II, Brookhaven National Lab, Upton, NY, USA
| | - Elio Vescovo
- National Synchrotron Light Source II, Brookhaven National Lab, Upton, NY, USA
| | - David Graf
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Xiaoyang Zhu
- Chemistry Department, Columbia University, New York, NY, USA
| | - Allen Scheie
- Neutron Scattering Division, Oak Ridge National Lab, Oak Ridge, TN, USA
- MPA-Q, Los Alamos National Lab, Los Alamos, NM, USA
| | - Andrew F May
- Materials Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, USA
| | - Olle Eriksson
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
- Wallenberg Initiative Materials Science for Sustainability, Uppsala University, Uppsala, Sweden
| | - D N Basov
- Physics Department, Columbia University, New York, NY, USA
| | - Cory R Dean
- Physics Department, Columbia University, New York, NY, USA
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free-Electron Laser Science and Department of Physics, Hamburg, Germany.
- Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departmento de Polímeros y Materiales Avanzados: Física, Química y Tecnología, Universidad del País Vasco (UPV/EHU), San Sebastián, Spain.
- Center for Computational Quantum Physics, Flatiron Institute, New York, NY, USA.
| | - Philip Kim
- Physics Department, Harvard University, Cambridge, MA, USA
| | | | - Andrew J Millis
- Physics Department, Columbia University, New York, NY, USA.
- Center for Computational Quantum Physics, Flatiron Institute, New York, NY, USA.
| | - Abhay N Pasupathy
- Physics Department, Columbia University, New York, NY, USA.
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, NY, USA.
| | - Xavier Roy
- Chemistry Department, Columbia University, New York, NY, USA.
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2
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Nakamura T, Sugihara H, Chen Y, Yukawa R, Ohtsubo Y, Tanaka K, Kitamura M, Kumigashira H, Kimura SI. Two-dimensional heavy fermion in a monoatomic-layer Kondo lattice YbCu 2. Nat Commun 2023; 14:7850. [PMID: 38040781 PMCID: PMC10692116 DOI: 10.1038/s41467-023-43662-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 11/16/2023] [Indexed: 12/03/2023] Open
Abstract
The Kondo effect between localized f-electrons and conductive carriers leads to exotic physical phenomena. Among them, heavy-fermion (HF) systems, in which massive effective carriers appear due to the Kondo effect, have fascinated many researchers. Dimensionality is also an important characteristic of the HF system, especially because it is strongly related to quantum criticality. However, the realization of the perfect two-dimensional (2D) HF materials is still a challenging topic. Here, we report the surface electronic structure of the monoatomic-layer Kondo lattice YbCu2 on a Cu(111) surface observed by synchrotron-based angle-resolved photoemission spectroscopy. The 2D conducting band and the Yb 4f state, located very close to the Fermi level, are observed. These bands are hybridized at low-temperature, forming the 2D HF state, with an evaluated coherence temperature of about 30 K. The effective mass of the 2D state is enhanced by a factor of 100 by the development of the HF state. Furthermore, clear evidence of the hybridization gap formation in the temperature dependence of the Kondo-resonance peak has been observed below the coherence temperature. Our study provides a new candidate as an ideal 2D HF material for understanding the Kondo effect at low dimensions.
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Affiliation(s)
- Takuto Nakamura
- Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan.
- Department of Physics, Graduate School of Science, Osaka University, Toyonaka, 560-0043, Japan.
| | - Hiroki Sugihara
- Department of Physics, Graduate School of Science, Osaka University, Toyonaka, 560-0043, Japan
| | - Yitong Chen
- Department of Physics, Graduate School of Science, Osaka University, Toyonaka, 560-0043, Japan
| | - Ryu Yukawa
- Graduate School of Engineering, Osaka University, Suita, 565-0871, Japan
| | - Yoshiyuki Ohtsubo
- National Institutes for Quantum Science and Technology, Sendai, 980-8579, Japan
| | | | - Miho Kitamura
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, 305-0801, Japan
| | - Hiroshi Kumigashira
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, 980-8577, Japan
| | - Shin-Ichi Kimura
- Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan.
- Department of Physics, Graduate School of Science, Osaka University, Toyonaka, 560-0043, Japan.
- Institute for Molecular Science, Okazaki, 444-8585, Japan.
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3
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Mihalyuk AN, Gruznev DV, Bondarenko LV, Tupchaya AY, Vekovshinin YE, Eremeev SV, Zotov AV, Saranin AA. A 2D heavy fermion CePb 3 kagome material on silicon: emergence of unique spin polarized states for spintronics. NANOSCALE 2022; 14:14732-14740. [PMID: 36172823 DOI: 10.1039/d2nr04280k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We report on the successful synthesis of a 2D atomically thin heavy-fermion CePb3 kagome compound on a Si(111) surface. Growth and morphology were controlled and characterized through scanning tunneling microscopy observations revealing the high crystalline quality of the sample. Angle-resolved photoelectron spectroscopy measurements revealed the giant highly-anisotropic Rashba-like spin splitting of the surface states and semi-metallic character of the spectrum. According to the DFT calculations, the occupied hole and unoccupied electron states with huge spin-orbit splitting and out-of-plane spin polarization reside at the M̄ points near the Fermi level EF, which is ≈100 meV above the experimental one. The out-of-plane FM magnetization was found to be preferred with Ce spin and orbital magnetic momenta values of 0.895μB and -0.840μB, respectively. The spin-split states near EF are primarily formed by Pb pxy orbitals with the admixing of Ce d and f electrons due to the Ce f-d hybridization acquired asymmetry with respect to the sign of k∥. The observed electronic structure of the CePb3/Si(111)√3 × √3 system is rather unique and in the hole-doped state, like in our experiment, can be enabled in the tunable spin current regime, which makes it a prospective 2D material for spintronic applications.
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Affiliation(s)
- Alexey N Mihalyuk
- Institute of Automation and Control Processes FEB RAS, 690041 Vladivostok, Russia.
- Institute of High Technologies and Advanced Materials, Far Eastern Federal University, 690950 Vladivostok, Russia
| | - Dimitry V Gruznev
- Institute of Automation and Control Processes FEB RAS, 690041 Vladivostok, Russia.
| | - Leonid V Bondarenko
- Institute of Automation and Control Processes FEB RAS, 690041 Vladivostok, Russia.
| | - Alexandra Y Tupchaya
- Institute of Automation and Control Processes FEB RAS, 690041 Vladivostok, Russia.
| | - Yuriy E Vekovshinin
- Institute of Automation and Control Processes FEB RAS, 690041 Vladivostok, Russia.
| | - Sergey V Eremeev
- Institute of Strength Physics and Materials Science, Tomsk 634055, Russia
| | - Andrey V Zotov
- Institute of Automation and Control Processes FEB RAS, 690041 Vladivostok, Russia.
| | - Alexander A Saranin
- Institute of Automation and Control Processes FEB RAS, 690041 Vladivostok, Russia.
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4
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Kang JH, Kim J, Park TB, Choi WS, Park S, Park T. Study on superconducting properties of CeIrIn 5thin films grown via pulsed laser deposition. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:455602. [PMID: 36055248 DOI: 10.1088/1361-648x/ac8f09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
We report the growth of CeIrIn5thin films with different crystal orientations on a MgF2(001) substrate using pulsed laser deposition technique. X-ray diffraction analysis showed that the thin films were either mainlya-axis-oriented (TF1) or a combination ofa- andc-axis-oriented (TF2). The characteristic features of heavy-fermion superconductors, i.e. Kondo coherence and superconductivity, were clearly observed, where the superconducting transition temperature (Tc) and Kondo coherence temperature (Tcoh) are 0.58 K and 41 K for TF1 and 0.52 K and 37 K for TF2, respectively. The temperature dependencies of the upper critical field (Hc2) of both thin films and the CeIrIn5single crystal revealed a scaling behavior, indicating that the nature of unconventional superconductivity has not been changed in the thin film. The successful synthesis of CeIrIn5thin films is expected to open a new avenue for novel quantum phases that may have been difficult to explore in the bulk crystalline samples.
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Affiliation(s)
- Ji-Hoon Kang
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jihyun Kim
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Tae Beom Park
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Woo Seok Choi
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sungmin Park
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Tuson Park
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
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5
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Naritsuka M, Terashima T, Matsuda Y. Controlling unconventional superconductivity in artificially engineered f-electron Kondo superlattices. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:273001. [PMID: 33946054 DOI: 10.1088/1361-648x/abfdf2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
Unconventional superconductivity and magnetism are intertwined on a microscopic level in a wide class of materials, including high-Tccuprates, iron pnictides, and heavy-fermion compounds. Interactions between superconducting electrons and bosonic fluctuations at the interface between adjacent layers in heterostructures provide a new approach to this most fundamental and hotly debated subject. We have been able to use a recent state-of-the-art molecular-beam-epitaxy technique to fabricate superlattices consisting of different heavy-fermion compounds with atomic thickness. These Kondo superlattices provide a unique opportunity to study the mutual interaction between unconventional superconductivity and magnetic order through the atomic interface. Here, we design and fabricate hybrid Kondo superlattices consisting of alternating layers of superconducting CeCoIn5withd-wave pairing symmetry and nonmagnetic metal YbCoIn5or antiferromagnetic heavy fermion metals such as CeRhIn5and CeIn3. In these Kondo superlattices, superconducting heavy electrons are confined within the two-dimensional CeCoIn5block layers and interact with neighboring nonmagnetic or magnetic layers through the interface. Superconductivity is strongly influenced by local inversion symmetry breaking at the interface in CeCoIn5/YbCoIn5superlattices. The superconducting and antiferromagnetic states coexist in spatially separated layers in CeCoIn5/CeRhIn5and CeCoIn5/CeIn3superlattices, but their mutual coupling via the interface significantly modifies the superconducting and magnetic properties. The fabrication of a wide variety of hybrid superlattices paves a new way to study the relationship between unconventional superconductivity and magnetism in strongly correlated materials.
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Affiliation(s)
- M Naritsuka
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Terashima
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Y Matsuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
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6
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Naritsuka M, Rosa PFS, Luo Y, Kasahara Y, Tokiwa Y, Ishii T, Miyake S, Terashima T, Shibauchi T, Ronning F, Thompson JD, Matsuda Y. Tuning the Pairing Interaction in a d-Wave Superconductor by Paramagnons Injected through Interfaces. PHYSICAL REVIEW LETTERS 2018; 120:187002. [PMID: 29775349 DOI: 10.1103/physrevlett.120.187002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Indexed: 06/08/2023]
Abstract
Unconventional superconductivity and magnetism are intertwined on a microscopic level in a wide class of materials. A new approach to this most fundamental and hotly debated issue focuses on the role of interactions between superconducting electrons and bosonic fluctuations at the interface between adjacent layers in heterostructures. Here we fabricate hybrid superlattices consisting of alternating atomic layers of the heavy-fermion superconductor CeCoIn_{5} and antiferromagnetic (AFM) metal CeRhIn_{5}, in which the AFM order can be suppressed by applying pressure. We find that the superconducting and AFM states coexist in spatially separated layers, but their mutual coupling via the interface significantly modifies the superconducting properties. An analysis of upper critical fields reveals that, upon suppressing the AFM order by applied pressure, the force binding superconducting electron pairs acquires an extreme strong-coupling nature. This demonstrates that superconducting pairing can be tuned nontrivially by magnetic fluctuations (paramagnons) injected through the interface.
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Affiliation(s)
- M Naritsuka
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - P F S Rosa
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - Yongkang Luo
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - Y Kasahara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Y Tokiwa
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
- Center for Electronic Correlations and Magnetism, Institute of Physics, Augsburg University, 86159 Augsburg, Germany
| | - T Ishii
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - S Miyake
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Terashima
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Shibauchi
- Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan
| | - F Ronning
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - J D Thompson
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - Y Matsuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
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