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Goldberg EC, Tacca MS, Flores F. A multi-orbital Hund's rules-based ionic Hamiltonian for transition metal atoms: high-order equation of motion method approach and Kondo resonances. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:475602. [PMID: 39106895 DOI: 10.1088/1361-648x/ad6bdc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 08/06/2024] [Indexed: 08/09/2024]
Abstract
A multi-orbital ionic Hamiltonian is presented to analyze the many-body properties of the d-transition metal atoms. This Hamiltonian considers all the atomic states obeying the first Hund's rule and also includes all orbital degeneracy, as well as the interaction of the atom with a metal. We analyze the solution of this ionic Hamiltonian by means of the equation of Motion method up to the fourth order,V4, in the atom-metal interaction. Equations for the appropriate Green-functions for analyzing the chemical and transport properties of the system are given for different atom occupancies. In particular, we introduce a full analysis of the multi-orbital Hamiltonian including atomic configurations withN, N+ 1 andN- 1 electrons, and discuss its Kondo properties. The shellsd1,d2andd3are analyzed in detail and Kondo energies are deduced in all these cases showing good agreement with the conventional known results.
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Affiliation(s)
- E C Goldberg
- Instituto de Física del Litoral. CONICET-UNL, Santa Fe, Argentina
- Uspallata s/N, Tanti (5155), Córdoba, Argentina
| | - M S Tacca
- Instituto de Física del Litoral. CONICET-UNL, Santa Fe, Argentina
| | - F Flores
- Departamento Física Teórica de la Materia Condensada, Condensed MatterPhysics Center (IFIMAC) University Autónoma de Madrid, E-28049 Madrid, Spain
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2
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Ryee S, Witt N, Wehling TO. Quenched Pair Breaking by Interlayer Correlations as a Key to Superconductivity in La_{3}Ni_{2}O_{7}. PHYSICAL REVIEW LETTERS 2024; 133:096002. [PMID: 39270168 DOI: 10.1103/physrevlett.133.096002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 06/05/2024] [Accepted: 07/29/2024] [Indexed: 09/15/2024]
Abstract
The recent discovery of superconductivity in La_{3}Ni_{2}O_{7} with T_{c}≃80 K under high pressure opens up a new route to high-T_{c} superconductivity. This material realizes a bilayer square lattice model featuring a strong interlayer hybridization unlike many unconventional superconductors. A key question in this regard concerns how electronic correlations driven by the interlayer hybridization affect the low-energy electronic structure and the concomitant superconductivity. Here, we demonstrate using a cluster dynamical mean-field theory that the interlayer electronic correlations (IECs) induce a Lifshitz transition resulting in a change of Fermi surface topology. By solving an appropriate gap equation, we further show that the leading pairing instability, s± wave, is enhanced by the IECs. The underlying mechanism is the quenching of a strong ferromagnetic channel, resulting from the Lifshitz transition driven by the IECs. Based on this picture, we provide a possible reason of why superconductivity emerges only under high pressure.
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3
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Li RS, Wang JT, Liu ZY, Zhou XH, Cao ZL, Xie Z. Electron correlation and relativistic effects on the electronic properties of a plutonium and americium mixed oxide (PuAmO 4): from single-particle approximation to dynamical mean-field theory. Phys Chem Chem Phys 2023; 25:30391-30404. [PMID: 37909910 DOI: 10.1039/d3cp02109b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
First-principles calculations were performed on a plutonium and americium mixed oxide (PuAmO4), aiming at revealing the effects of electron correlation, Pu/Am 5f-conduction electrons' hybridization, and relativity on its electronic properties. The many-body calculation suggests that the spin-orbit-coupling (SOC)-splitting of j = 5/2 and j = 7/2 manifolds are both in the weakly and moderately correlated states, respectively, implying that the jj coupling scheme is more appropriate for Pu/Am 5f electrons. The density of states, 5f occupation numbers, and Green's functions all suggest that both Pu and Am 5f electrons exhibit the coexistence of the localized and delocalized states. The admixture of 5fn atomic configurations, Pu/Am 5f-conduction electrons' hybridization, and dual characteristics of 5f electrons yield average occupation numbers of 5f electrons n5f = 4.78 and 5.86 for Pu and Am ions, respectively. Within the DFT+DMFT calculation, the weighted-summation-derived occupation numbers in terms of 5f4/5f5/5f6 and 5f5/5f6 configurations for Pu and Am 5f electrons, respectively, are in reasonable agreement with those of other DFT-based calculations.
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Affiliation(s)
- Ru-Song Li
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi'an 710123, China.
| | - Jin-Tao Wang
- School of Nuclear Engineering, Xi'an Research Institute of High Technology, Xi'an 710025, China
| | - Zhi-Yong Liu
- Beijing Research Institute of High Technology, Beijing 100077, China
| | - Xiao-Hua Zhou
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi'an 710123, China.
| | - Ze-Lin Cao
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Electronic Information, Xijing University, Xi'an 710123, China.
| | - Zheng Xie
- College of Rare Earth and Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, P. R. China.
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4
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Semeniuk K, Chang H, Baglo J, Friedemann S, Tozer SW, Coniglio WA, Gamża MB, Reiss P, Alireza P, Leermakers I, McCollam A, Grockowiak AD, Grosche FM. Truncated mass divergence in a Mott metal. Proc Natl Acad Sci U S A 2023; 120:e2301456120. [PMID: 37695907 PMCID: PMC10515144 DOI: 10.1073/pnas.2301456120] [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: 01/26/2023] [Accepted: 07/18/2023] [Indexed: 09/13/2023] Open
Abstract
The Mott metal-insulator transition represents one of the most fundamental phenomena in condensed matter physics. Yet, basic tenets of the canonical Brinkman-Rice picture of Mott localization remain to be tested experimentally by quantum oscillation measurements that directly probe the quasiparticle Fermi surface and effective mass. By extending this technique to high pressure, we have examined the metallic state on the threshold of Mott localization in clean, undoped crystals of NiS2. We find that i) on approaching Mott localization, the quasiparticle mass is strongly enhanced, whereas the Fermi surface remains essentially unchanged; ii) the quasiparticle mass closely follows the divergent form predicted theoretically, establishing charge carrier slowdown as the driver for the metal-insulator transition; iii) this mass divergence is truncated by the metal-insulator transition, placing the Mott critical point inside the insulating section of the phase diagram. The inaccessibility of the Mott critical point in NiS2 parallels findings at the threshold of ferromagnetism in clean metallic systems, in which criticality at low temperature is almost universally interrupted by first-order transitions or novel emergent phases such as incommensurate magnetic order or unconventional superconductivity.
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Affiliation(s)
- Konstantin Semeniuk
- Cavendish Laboratory, University of Cambridge, CambridgeCB3 0HE, United Kingdom
- Max Planck Institute for Chemical Physics of Solids, Dresden01187, Germany
| | - Hui Chang
- Cavendish Laboratory, University of Cambridge, CambridgeCB3 0HE, United Kingdom
| | - Jordan Baglo
- Cavendish Laboratory, University of Cambridge, CambridgeCB3 0HE, United Kingdom
- Department of Physics, Université de Sherbrooke, SherbrookeJ1K 2R1, Canada
| | - Sven Friedemann
- H H Wills Laboratory, University of Bristol, BristolBS8 1TL, United Kingdom
| | | | | | - Monika B. Gamża
- Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy, University of Central Lancashire, PrestonPR1 2HE, United Kingdom
| | - Pascal Reiss
- Cavendish Laboratory, University of Cambridge, CambridgeCB3 0HE, United Kingdom
- Max Planck Institute for Solid State Research, Stuttgart70569, Germany
| | - Patricia Alireza
- Cavendish Laboratory, University of Cambridge, CambridgeCB3 0HE, United Kingdom
| | - Inge Leermakers
- High Field Magnet Laboratory, Radboud University, Nijmegen6525 ED, The Netherlands
| | - Alix McCollam
- High Field Magnet Laboratory, Radboud University, Nijmegen6525 ED, The Netherlands
| | - Audrey D. Grockowiak
- National High Magnetic Field Laboratory, Tallahassee, FL83810
- Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069Dresden, Germany
| | - F. Malte Grosche
- Cavendish Laboratory, University of Cambridge, CambridgeCB3 0HE, United Kingdom
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5
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Turco E, Bernhardt A, Krane N, Valenta L, Fasel R, Juríček M, Ruffieux P. Observation of the Magnetic Ground State of the Two Smallest Triangular Nanographenes. JACS AU 2023; 3:1358-1364. [PMID: 37234116 PMCID: PMC10207087 DOI: 10.1021/jacsau.2c00666] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/02/2023] [Accepted: 02/02/2023] [Indexed: 05/27/2023]
Abstract
Fusion of three benzene rings in a triangular fashion gives rise to the smallest open-shell graphene fragment, the phenalenyl radical, whose π-extension leads to an entire family of non-Kekulé triangular nanographenes with high-spin ground states. Here, we report the first synthesis of unsubstituted phenalenyl on a Au(111) surface, which is achieved by combining in-solution synthesis of the hydro-precursor and on-surface activation by atomic manipulation, using the tip of a scanning tunneling microscope. Single-molecule structural and electronic characterizations confirm its open-shell S = 1/2 ground state that gives rise to Kondo screening on the Au(111) surface. In addition, we compare the phenalenyl's electronic properties with those of triangulene, the second homologue in the series, whose S = 1 ground state induces an underscreened Kondo effect. Our results set a new lower size limit in the on-surface synthesis of magnetic nanographenes that can serve as building blocks for the realization of new exotic quantum phases of matter.
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Affiliation(s)
- Elia Turco
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Annika Bernhardt
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Nils Krane
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Leoš Valenta
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Roman Fasel
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
- Department
of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Michal Juríček
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Pascal Ruffieux
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
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6
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Ryee S, Wehling TO. Switching between Mott-Hubbard and Hund Physics in Moiré Quantum Simulators. NANO LETTERS 2023; 23:573-579. [PMID: 36622289 DOI: 10.1021/acs.nanolett.2c04169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Mott-Hubbard and Hund electron correlations have been realized thus far in separate classes of materials. Here, we show that a single moiré homobilayer encompasses both kinds of physics in a controllable manner. We develop a microscopic multiband model that we solve by dynamical mean-field theory to nonperturbatively address the local many-body correlations. We demonstrate how tuning with twist angle, dielectric screening, and hole density allows us to switch between Mott-Hubbard and Hund correlated states in a twisted WSe2 bilayer. The underlying mechanism is based on controlling Coulomb-interaction-driven orbital polarization and the energetics of concomitant local singlet and triplet spin configurations. From a comparison to recent experimental transport data, we find signatures of a filling-controlled transition from a triplet charge-transfer insulator to a Hund-Mott metal. Our finding establishes twisted transition-metal dichalcogenides as a tunable platform for exotic phases of quantum matter emerging from large local spin moments.
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Affiliation(s)
- Siheon Ryee
- I. Institute of Theoretical Physics, University of Hamburg, Notkestrasse 9, 22607Hamburg, Germany
| | - Tim O Wehling
- I. Institute of Theoretical Physics, University of Hamburg, Notkestrasse 9, 22607Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany
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7
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Li RS, Liu ZY, Wang YM, Li S, Zhang PJ, Cao ZL. Inter-configuration fluctuation for 5f electrons in uranium hexafluoride: A many-body study. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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8
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Mixed 5f atomic configurations in two polymorphic forms of uranium pentafluoride. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2021.139240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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9
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Direct observation of kink evolution due to Hund's coupling on approach to metal-insulator transition in NiS 2-xSe x. Nat Commun 2021; 12:1208. [PMID: 33623023 PMCID: PMC7902648 DOI: 10.1038/s41467-021-21460-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 01/15/2021] [Indexed: 11/24/2022] Open
Abstract
Understanding characteristic energy scales is a fundamentally important issue in the study of strongly correlated systems. In multiband systems, an energy scale is affected not only by the effective Coulomb interaction but also by the Hund’s coupling. Direct observation of such energy scale has been elusive so far in spite of extensive studies. Here, we report the observation of a kink structure in the low energy dispersion of NiS2−xSex and its characteristic evolution with x, by using angle resolved photoemission spectroscopy. Dynamical mean field theory calculation combined with density functional theory confirms that this kink originates from Hund’s coupling. We find that the abrupt deviation from the Fermi liquid behavior in the electron self-energy results in the kink feature at low energy scale and that the kink is directly related to the coherence-incoherence crossover temperature scale. Our results mark the direct observation of the evolution of the characteristic temperature scale via kink features in the spectral function, which is the hallmark of Hund’s physics in the multiorbital system. A decisive spectroscopic evidence of the Hund’s coupling energy scale in multi-orbital correlated systems has been lacking. Here, the authors identify a kink feature due to Hund´s coupling in the spectral function of NiS2xSex as they track its evolution across the Mott-insulator transition.
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10
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Li RS, Xie Z, Kong LY, Hou SX, Luo JJ, Xin DQ. Intermediate occupation numbers for 5f electrons in a Pu and U mixed oxide. Phys Chem Chem Phys 2021; 23:14725-14736. [PMID: 34190242 DOI: 10.1039/d1cp01149a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In order to reveal the correlation effect on the electronic properties in particular 5f electron occupation numbers of Pu/U ions in a (Pu,U) mixed oxide-PuUO4, a first principles calculation is performed by using density functional theory (DFT) plus a dynamical mean field theory (DMFT) scheme with the spin-orbit coupling (SOC) and on-site Coulomb repulsion for correlation effect due to localized Pu/U 5f orbitals. Results demonstrate that Pu/U 5f electron occupation numbers in the ground state of PuUO4 are mainly composed of 5f4/5f5 and 5f2/5f3 configurations, and exhibiting the intermediate occupation (IO) numbers with average 5f occupation numbers of about nf = 4.879 and 2.423 for Pu and U ions, respectively, irrespective of different Pu and U lattice sites in PuUO4. Pu 5f j = 5/2 and j = 7/2 components are in moderately and weakly correlated states, respectively, while U 5f j = 5/2 and j = 7/2 manifolds are both in weakly correlated states. jj and LS coupling schemes are feasible for Pu and U 5f electrons, respectively. In order to directly compare with the experimental angle-resolved photoemission spectrum (ARPES), we also estimate the momentum-resolved electronic spectrum function for this system.
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Affiliation(s)
- Ru-Song Li
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Science, Xijing University, Xi'an 710123, China.
| | - Zheng Xie
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Science, Xijing University, Xi'an 710123, China.
| | - Ling-Yun Kong
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Science, Xijing University, Xi'an 710123, China.
| | - Su-Xia Hou
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Science, Xijing University, Xi'an 710123, China.
| | - Ji-Jun Luo
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Science, Xijing University, Xi'an 710123, China.
| | - Du-Qiang Xin
- Shaanxi Engineering Research Center of Controllable Neutron Source, School of Science, Xijing University, Xi'an 710123, China.
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11
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Huang B, Liu Z, Han Y, Zhao S, Wu M, Frank CE, Greenblatt M, Croft M, Quackenbush NF, Liu S, Tyson TA, Zhang L, Sun J, Shan P, Dai J, Yu X, Cheng J, Li MR. Nonmetallic metal toward a pressure-induced bad-metal state in two-dimensional Cu 3LiRu 2O 6. Chem Commun (Camb) 2020; 56:265-268. [DOI: 10.1039/c9cc06691h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The two-dimensional honeycomb layered nonmetallic metal Cu3LiRu2O6 exhibits Pauli-like paramagnetic and Mott variable range hopping semiconduction behaviors, which can be significantly suppressed toward a bad-metal state by pressure up to 35 GPa.
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12
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Danu B, Assaad FF, Mila F. Exploring the Kondo Effect of an Extended Impurity with Chains of Co Adatoms in a Magnetic Field. PHYSICAL REVIEW LETTERS 2019; 123:176601. [PMID: 31702259 DOI: 10.1103/physrevlett.123.176601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Indexed: 06/10/2023]
Abstract
Motivated by recent STM experiments, we explore the magnetic field induced Kondo effect that takes place at symmetry protected level crossings in finite Co adatom chains. We argue that the effective two-level system realized at a level crossing acts as an extended impurity coupled to the conduction electrons of the substrate by a distribution of Kondo couplings at the sites of the chain. Using auxiliary-field quantum Monte Carlo simulations, which quantitatively reproduce the field dependence of the zero-bias signal, we show that a proper Kondo resonance is present at the sites where the effective Kondo coupling dominates. Our modeling and numerical simulations provide a theoretical basis for the interpretation of the STM spectrum in terms of level crossings of the Co adatom chains.
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Affiliation(s)
- Bimla Danu
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Fakher F Assaad
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, D-97074 Würzburg, Germany
| | - Frédéric Mila
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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13
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Huddart BM, Birch MT, Pratt FL, Blundell SJ, Porter DG, Clark SJ, Wu W, Julian SR, Hatton PD, Lancaster T. Local magnetism, magnetic order and spin freezing in the 'nonmetallic metal' FeCrAs. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:285803. [PMID: 30933932 DOI: 10.1088/1361-648x/ab151f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present the results of x-ray scattering and muon-spin relaxation ([Formula: see text]SR) measurements on the iron-pnictide compound FeCrAs. Polarized non-resonant magnetic x-ray scattering results reveal the 120° periodicity expected from the suggested three-fold symmetric, non-collinear antiferromagnetic structure. [Formula: see text]SR measurements indicate a magnetically ordered phase throughout the bulk of the material below [Formula: see text] K. There are signs of fluctuating magnetism in a narrow range of temperatures above [Formula: see text] involving low-energy excitations, while at temperatures well below [Formula: see text] behaviour characteristic of freezing of dynamics is observed, likely reflecting the effect of disorder in our polycrystalline sample. Using density functional theory we propose a distinct muon stopping site in this compound and assess the degree of distortion induced by the implanted muon.
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Affiliation(s)
- B M Huddart
- Centre for Materials Physics, Durham University, Durham DH1 3LE, United Kingdom
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14
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Shafeie S, Guo S, Erhart P, Hu Q, Palmqvist A. Balancing Scattering Channels: A Panoscopic Approach toward Zero Temperature Coefficient of Resistance Using High-Entropy Alloys. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805392. [PMID: 30407664 DOI: 10.1002/adma.201805392] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/11/2018] [Indexed: 06/08/2023]
Abstract
Designing alloys with an accurate temperature-independent electrical response over a wide temperature range, specifically a low temperature coefficient of resistance (TCR), remains a big challenge from a material design point of view. More than a century after their discovery, Constantan (Cu-Ni) and Manganin (Cu-Mn-Ni) alloys remain the top choice for strain gauge applications and high-quality resistors up to 473-573 K. Here, an average TCR is demonstrated that is up to ≈800 times smaller in the temperature range 5-300 K and >800 times smaller than for any of these standard materials over a wide temperature range (5 K < T < 1200 K). This is achieved for selected compositions of Alx CoCrFeNi high-entropy alloys (HEAs), for which a strong correlation of the ultralow TCR is established with the underlying microstructure and its local composition. The exceptionally low electron-phonon coupling expected in these HEAs is crucial for developing novel devices, e.g., hot-electron detectors, high-Q resonant antennas, and materials in gravitational wave detectors.
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Affiliation(s)
- Samrand Shafeie
- Department of Industrial and Materials Science, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Sheng Guo
- Department of Industrial and Materials Science, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Paul Erhart
- Department of Physics, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Qiang Hu
- Institute of Applied Physics, Jiangxi Academy of Sciences, Nanchang, 330029, P. R. China
| | - Anders Palmqvist
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
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15
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16
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Tomczak JM. Thermoelectricity in correlated narrow-gap semiconductors. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:183001. [PMID: 29633717 DOI: 10.1088/1361-648x/aab284] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We review many-body effects, their microscopic origin, as well as their impact on thermoelectricity in correlated narrow-gap semiconductors. Members of this class-such as FeSi and FeSb2-display an unusual temperature dependence in various observables: insulating with large thermopowers at low temperatures, they turn bad metals at temperatures much smaller than the size of their gaps. This insulator-to-metal crossover is accompanied by spectral weight-transfers over large energies in the optical conductivity and by a gradual transition from activated to Curie-Weiss-like behaviour in the magnetic susceptibility. We show a retrospective of the understanding of these phenomena, discuss the relation to heavy-fermion Kondo insulators-such as Ce3Bi4Pt3 for which we present new results-and propose a general classification of paramagnetic insulators. From the latter, FeSi emerges as an orbital-selective Kondo insulator. Focussing on intermetallics such as silicides, antimonides, skutterudites, and Heusler compounds we showcase successes and challenges for the realistic simulation of transport properties in the presence of electronic correlations. Further, we explore new avenues in which electronic correlations may contribute to the improvement of thermoelectric performance.
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Affiliation(s)
- Jan M Tomczak
- Institute of Solid State Physics, TU Wien, A-1040 Vienna, Austria
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17
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Komijani Y, Coleman P. Model for a Ferromagnetic Quantum Critical Point in a 1D Kondo Lattice. PHYSICAL REVIEW LETTERS 2018; 120:157206. [PMID: 29756902 DOI: 10.1103/physrevlett.120.157206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Indexed: 06/08/2023]
Abstract
Motivated by recent experiments, we study a quasi-one-dimensional model of a Kondo lattice with ferromagnetic coupling between the spins. Using bosonization and dynamical large-N techniques, we establish the presence of a Fermi liquid and a magnetic phase separated by a local quantum critical point, governed by the Kondo breakdown picture. Thermodynamic properties are studied and a gapless charged mode at the quantum critical point is highlighted.
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Affiliation(s)
- Yashar Komijani
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Piers Coleman
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
- Department of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX, United Kingdom
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18
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Hausoel A, Karolak M, Şaşιoğlu E, Lichtenstein A, Held K, Katanin A, Toschi A, Sangiovanni G. Local magnetic moments in iron and nickel at ambient and Earth's core conditions. Nat Commun 2017; 8:16062. [PMID: 28799538 PMCID: PMC5510222 DOI: 10.1038/ncomms16062] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 05/25/2017] [Indexed: 12/01/2022] Open
Abstract
Some Bravais lattices have a particular geometry that can slow down the motion of Bloch electrons by pre-localization due to the band-structure properties. Another known source of electronic localization in solids is the Coulomb repulsion in partially filled d or f orbitals, which leads to the formation of local magnetic moments. The combination of these two effects is usually considered of little relevance to strongly correlated materials. Here we show that it represents, instead, the underlying physical mechanism in two of the most important ferromagnets: nickel and iron. In nickel, the van Hove singularity has an unexpected impact on the magnetism. As a result, the electron-electron scattering rate is linear in temperature, in violation of the conventional Landau theory of metals. This is true even at Earth's core pressures, at which iron is instead a good Fermi liquid. The importance of nickel in models of geomagnetism may have therefore to be reconsidered.
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Affiliation(s)
- A. Hausoel
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - M. Karolak
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - E. Şaşιoğlu
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
- Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - A. Lichtenstein
- Institut für Theoretische Physik, Universität Hamburg, Jungiusstrasse 9, 20355 Hamburg, Germany
| | - K. Held
- Institute of Solid State Physics, TU Wien, 1040 Vienna, Austria
| | - A. Katanin
- M. N. Mikheev Institute of Metal Physics, 620990 Ekaterinburg, Russia
- Ural Federal University, 620002 Ekaterinburg, Russia
| | - A. Toschi
- Institute of Solid State Physics, TU Wien, 1040 Vienna, Austria
| | - G. Sangiovanni
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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19
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Karolak M, Jacob D. Effects of valence, geometry and electronic correlations on transport in transition metal benzene sandwich molecules. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:445301. [PMID: 27605217 DOI: 10.1088/0953-8984/28/44/445301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We study the impact of the valence and the geometry on the electronic structure and transport properties of different transition metal-benzene sandwich molecules bridging the tips of a Cu nanocontact. Our density-functional calculations show that the electronic transport properties of the molecules depend strongly on the molecular geometry which can be controlled by the nanocontact tips. Depending on the valence of the transition metal center certain molecules can be tuned in and out of half-metallic behaviour facilitating potential spintronics applications. We also discuss our results in the framework of an Anderson impurity model, indicating cases where the inclusion of local correlations alters the ground state qualitatively. For Co and V centered molecules we find indications of an orbital Kondo effect.
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Affiliation(s)
- M Karolak
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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20
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Hoshino S, Werner P. Superconductivity from Emerging Magnetic Moments. PHYSICAL REVIEW LETTERS 2015; 115:247001. [PMID: 26705649 DOI: 10.1103/physrevlett.115.247001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Indexed: 06/05/2023]
Abstract
Multiorbital Hubbard models are shown to exhibit a spatially isotropic spin-triplet superconducting phase, where equal-spin electrons in different local orbitals are paired. This superconducting state is stabilized in the spin-freezing crossover regime, where local moments emerge in the metal phase, and the pairing is substantially assisted by spin anisotropy. The phase diagram features a superconducting dome below a non-Fermi-liquid metallic region and next to a magnetically ordered phase. We suggest that this type of fluctuating-moment-induced superconductivity, which is not originating from fluctuations near a quantum critical point, may be realized in spin-triplet superconductors such as strontium ruthenates and uranium compounds.
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Affiliation(s)
- Shintaro Hoshino
- Department of Basic Science, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
- Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland
| | - Philipp Werner
- Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland
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21
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Khajetoorians AA, Valentyuk M, Steinbrecher M, Schlenk T, Shick A, Kolorenc J, Lichtenstein AI, Wehling TO, Wiesendanger R, Wiebe J. Tuning emergent magnetism in a Hund's impurity. NATURE NANOTECHNOLOGY 2015; 10:958-64. [PMID: 26344182 DOI: 10.1038/nnano.2015.193] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 07/27/2015] [Indexed: 05/27/2023]
Abstract
The recently proposed concept of a Hund's metal--a metal in which electron correlations are driven by Hund's rule coupling-can be used to explain the exotic magnetic and electronic behaviour of strongly correlated electron systems of multi-orbital metallic materials. Tuning the abundance of parameters that determine these materials is, however, experimentally challenging. Here, we show that the basic constituent of a Hund's metal--a Hund's impurity--can be realized using a single iron atom adsorbed on a platinum surface, a system that comprises a magnetic moment in the presence of strong charge fluctuations. The magnetic properties can be controlled by using the tip of a scanning tunnelling microscope to change the binding site and degree of hydrogenation of the 3d transition-metal atom. We are able to experimentally explore a regime of four almost degenerate energy scales (Zeeman energy, temperature, Kondo temperature and magnetic anisotropy) and probe the magnetic excitations with the microscope tip. The regime of our Hund's impurity can be tuned from an emergent magnetic moment to a multi-orbital Kondo state, and the system could be used to test predictions of advanced many-body theories for non-Fermi liquids in quantum magnets or unconventional superconductors.
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Affiliation(s)
- A A Khajetoorians
- Department of Physics, Hamburg University, Hamburg D-20355, Germany
- Institute for Molecules and Materials (IMM), Radboud University, Nijmegen 6525 AJ, The Netherlands
| | - M Valentyuk
- Institute of Theoretical Physics, Hamburg University, Hamburg D-20355, Germany
- Department of Theoretical Physics and Applied Mathematics, Ural Federal University, Ekaterinburg 620002, Russia
| | - M Steinbrecher
- Department of Physics, Hamburg University, Hamburg D-20355, Germany
| | - T Schlenk
- Department of Physics, Hamburg University, Hamburg D-20355, Germany
| | - A Shick
- Institute of Physics, ASCR, Na Slovance 2, Prague CZ-18221, Czech Republic
| | - J Kolorenc
- Institute of Physics, ASCR, Na Slovance 2, Prague CZ-18221, Czech Republic
| | - A I Lichtenstein
- Institute of Theoretical Physics, Hamburg University, Hamburg D-20355, Germany
| | - T O Wehling
- Institute for Theoretical Physics, Bremen Center for Computational Material Science, University of Bremen, Bremen D-28359, Germany
| | - R Wiesendanger
- Department of Physics, Hamburg University, Hamburg D-20355, Germany
| | - J Wiebe
- Department of Physics, Hamburg University, Hamburg D-20355, Germany
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22
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Hirjibehedin CF. Magnetic atoms: The makings of a Hund's metal. NATURE NANOTECHNOLOGY 2015; 10:914-915. [PMID: 26530020 DOI: 10.1038/nnano.2015.225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Cyrus F Hirjibehedin
- London Centre for Nanotechnology, Department of Physics and Astronomy, Department of Chemistry, University College London, London WC1H 0AH, UK
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23
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Prüser H, Dargel PE, Bouhassoune M, Ulbrich RG, Pruschke T, Lounis S, Wenderoth M. Interplay between the Kondo effect and the Ruderman-Kittel-Kasuya-Yosida interaction. Nat Commun 2014; 5:5417. [PMID: 25384417 DOI: 10.1038/ncomms6417] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 09/30/2014] [Indexed: 11/09/2022] Open
Abstract
The interplay between the Ruderman-Kittel-Kasuya-Yosida interaction and the Kondo effect is expected to provide the driving force for the emergence of many phenomena in strongly correlated electron materials. Two magnetic impurities in a metal are the smallest possible system containing all these ingredients and define a bottom-up approach towards a long-term understanding of concentrated/dense systems. Here we report on the experimental and theoretical investigation of iron dimers buried below a Cu(100) surface by means of low-temperature scanning tunnelling spectroscopy combined with density functional theory and numerical renormalization group calculations. The Kondo effect, in particular the width of the Abrikosov-Suhl resonance, is strongly altered or even suppressed due to magnetic coupling between the impurities. It oscillates as a function of dimer separation revealing that it is related to indirect exchange interactions mediated by the conduction electrons.
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Affiliation(s)
- Henning Prüser
- 4. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Piet E Dargel
- Institut für Theoretische Physik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Mohammed Bouhassoune
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - Rainer G Ulbrich
- 4. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Thomas Pruschke
- Institut für Theoretische Physik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Samir Lounis
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - Martin Wenderoth
- 4. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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24
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Kügel J, Karolak M, Senkpiel J, Hsu PJ, Sangiovanni G, Bode M. Relevance of hybridization and filling of 3d orbitals for the Kondo effect in transition metal phthalocyanines. NANO LETTERS 2014; 14:3895-902. [PMID: 24871813 DOI: 10.1021/nl501150k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Magnetic organic molecules, such as 3d transition metal phthalocyanines (TMPc), exhibit properties which make them promising candidates for future applications in magnetic data storage or spin-based data processing. Due to their small size, however, TMPc molecules are prone to quantum effects. For example, the interaction of uncompensated molecular spins with conduction electrons of the substrate may lead to the formation of a many-body singlet state, which gives rise to the so-called Kondo effect. Although the Kondo effect of TMPc molecules has been the object of several investigations, a consistent picture to describe under which conditions a Kondo state is formed is still missing. Here, we study the Kondo properties of MnPc on Ag(001) by means of the low-temperature scanning tunneling spectroscopy (LT-STS) measurements. Differential conductance dI/dU spectra reveal a zero-bias peak that is localized on the Mn ion site. Ab initio calculations combined with a many-body treatment of the multiorbital interaction show that the local Hund coupling favors the high-spin configuration on the 3d shell of the central TM atom. Therefore, each orbital gets close to its individual half-filling creating the necessary condition for many of the 3d orbitals to contribute to the observed Kondo resonance. This, however, happens only for the 3dz(2) orbital, whose hybridization to the substrate is much stronger than for the other orbitals thanks to its shape and its orientation.
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Affiliation(s)
- Jens Kügel
- Physikalisches Institut, Experimentelle Physik 2, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
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25
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Gardonio S, Karolak M, Wehling TO, Petaccia L, Lizzit S, Goldoni A, Lichtenstein AI, Carbone C. Excitation spectra of transition-metal atoms on the Ag (100) surface controlled by Hund's exchange. PHYSICAL REVIEW LETTERS 2013; 110:186404. [PMID: 23683227 DOI: 10.1103/physrevlett.110.186404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Indexed: 06/02/2023]
Abstract
We report photoemission experiments revealing the valence electron spectral function of Mn, Fe, Co, and Ni atoms on the Ag (100) surface. The series of spectra shows splittings of higher energy features which decrease with the filling of the 3d shell and a highly nonmonotonic evolution of spectral weight near the Fermi edge. First principles calculations demonstrate that two manifestations of Hund's exchange J are responsible for this evolution. First, there is a monotonic reduction of the effective exchange splittings with increasing filling of the 3d shell. Second, the amount of charge fluctuations and, thus, the weight of quasiparticle peaks at the Fermi level varies nonmonotonically through this 3d series due to a distinct occupancy dependence of effective charging energies U(eff).
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Affiliation(s)
- S Gardonio
- Materials Research Laboratory, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia
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26
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Bayat A, Bose S, Sodano P, Johannesson H. Entanglement probe of two-impurity Kondo physics in a spin chain. PHYSICAL REVIEW LETTERS 2012; 109:066403. [PMID: 23006288 DOI: 10.1103/physrevlett.109.066403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/16/2012] [Indexed: 06/01/2023]
Abstract
We propose that real-space properties of the two-impurity Kondo model can be obtained from an effective spin model where two single-impurity Kondo spin chains are joined via an Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the two impurity spins. We then use a density matrix renormalization group approach, valid in all ranges of parameters, to study its features using two complementary quantum-entanglement measures, the negativity and the von Neumann entropy. This nonperturbative approach enables us to uncover the precise dependence of the spatial extent ξ(K) of the Kondo screening cloud with the Kondo and RKKY couplings. Our results reveal an exponential suppression of the Kondo temperature T(K)~1/ξ(K) with the size of the effective impurity spin in the limit of large ferromagnetic RKKY coupling, a striking display of "Kondo resonance narrowing" in the two-impurity Kondo model. We also show how the antiferromagnetic RKKY interaction produces an effective decoupling of the impurities from the bulk already for intermediate strengths of this interaction, and, furthermore, exhibit how the non-Fermi liquid quantum critical point is signaled in the quantum entanglement between various parts of the system.
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Affiliation(s)
- Abolfazl Bayat
- Institut für Theoretische Physik, Universität Ulm, Ulm, Germany
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27
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Ong TT, Coleman P. Local quantum criticality of an iron-pnictide tetrahedron. PHYSICAL REVIEW LETTERS 2012; 108:107201. [PMID: 22463447 DOI: 10.1103/physrevlett.108.107201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Indexed: 05/31/2023]
Abstract
Motivated by the close correlation between transition temperature (T(c)) and the tetrahedral bond angle of the As-Fe-As layer observed in the iron-based superconductors, we study the interplay between spin and orbital physics of an isolated iron-arsenide tetrahedron embedded in a metallic environment. Whereas the spin-Kondo effect is suppressed to low temperatures by Hund's coupling, the orbital degrees of freedom are expected to quantum mechanically quench at high temperatures, giving rise to an overscreened, non-Fermi liquid ground state. Translated into a dense environment, this critical state may play an important role in the superconductivity of these materials.
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Affiliation(s)
- T Tzen Ong
- Center for Materials Theory, Department of Physics & Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
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28
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de' Medici L, Mravlje J, Georges A. Janus-faced influence of Hund's rule coupling in strongly correlated materials. PHYSICAL REVIEW LETTERS 2011; 107:256401. [PMID: 22243094 DOI: 10.1103/physrevlett.107.256401] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Indexed: 05/31/2023]
Abstract
We show that in multiband metals the correlations are strongly affected by Hund's rule coupling, which depending on the filling promotes metallic, insulating or bad-metallic behavior. The quasiparticle coherence and the proximity to a Mott insulator are influenced distinctly and, away from single- and half-filling, in opposite ways. A strongly correlated bad metal far from a Mott phase is found there. We propose a concise classification of 3d and 4d transition-metal oxides within which the ubiquitous occurrence of strong correlations in Ru- and Cr-based oxides, as well as the recently measured high Néel temperatures in Tc-based perovskites are naturally explained.
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Affiliation(s)
- Luca de' Medici
- Laboratoire de Physique des Solides, UMR8502 CNRS-Université Paris-Sud, Orsay, France
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29
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Karolak M, Jacob D, Lichtenstein AI. Orbital Kondo effect in cobalt-benzene sandwich molecules. PHYSICAL REVIEW LETTERS 2011; 107:146604. [PMID: 22107224 DOI: 10.1103/physrevlett.107.146604] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Indexed: 05/31/2023]
Abstract
We study a Co-benzene sandwich molecule bridging the tips of a Cu nanocontact as a realistic model of correlated molecular transport. To this end we employ a recently developed method for calculating the correlated electronic structure and transport properties of nanoscopic conductors. When the molecule is slightly compressed by the tips of the nanocontact the dynamic correlations originating from the strongly interacting Co 3d shell give rise to an orbital Kondo effect while the usual spin Kondo effect is suppressed due to Hund's rule coupling. This nontrivial Kondo effect produces a sharp and temperature-dependent Abrikosov-Suhl resonance in the spectral function at the Fermi level and a corresponding Fano line shape in the low bias conductance.
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Affiliation(s)
- M Karolak
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, D-20355 Hamburg, Germany
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30
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Mravlje J, Aichhorn M, Miyake T, Haule K, Kotliar G, Georges A. Coherence-incoherence crossover and the mass-renormalization puzzles in Sr(2)RuO(4). PHYSICAL REVIEW LETTERS 2011; 106:096401. [PMID: 21405640 DOI: 10.1103/physrevlett.106.096401] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Indexed: 05/30/2023]
Abstract
We calculate the electronic structure of Sr(2)RuO(4), treating correlations within dynamical mean-field theory. The approach successfully reproduces several experimental results and explains the key properties of this material: the anisotropic mass renormalization of quasiparticles and the crossover into an incoherent regime above a low temperature scale. While the orbital differentiation originates from the proximity of the van Hove singularity, strong correlations are caused by the Hund's coupling. The generality of this mechanism for other correlated materials is pointed out.
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Affiliation(s)
- Jernej Mravlje
- Centre de Physique Théorique, École Polytechnique, CNRS, Palaiseau, France
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31
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Matsumoto Y, Nakatsuji S, Kuga K, Karaki Y, Horie N, Shimura Y, Sakakibara T, Nevidomskyy AH, Coleman P. Quantum Criticality Without Tuning in the Mixed Valence Compound β-YbAlB
4. Science 2011; 331:316-9. [PMID: 21252341 DOI: 10.1126/science.1197531] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Yosuke Matsumoto
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Satoru Nakatsuji
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Kentaro Kuga
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Yoshitomo Karaki
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Naoki Horie
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Yasuyuki Shimura
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Toshiro Sakakibara
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Andriy H. Nevidomskyy
- Center for Materials Theory, Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | - Piers Coleman
- Center for Materials Theory, Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA
- Department of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
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