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Hrodmarsson HR, Garcia GA, Linnartz H, Nahon L. VUV photoionization dynamics of the C 60 buckminsterfullerene: 2D-matrix photoelectron spectroscopy in an astrophysical context. Phys Chem Chem Phys 2020; 22:13880-13892. [PMID: 32396927 DOI: 10.1039/d0cp01210f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present the photoionization dynamics of the C60 buckminsterfullerene from threshold up to 14.0 eV recorded with VUV synchrotron radiation at the DESIRS beamline at the SOLEIL synchrotron. The recorded data is obtained using a double-imaging photoelectron photoion coincidence spectrometer and is presented as a two-dimensional photoelectron matrix which contains a wealth of spectroscopic data. We present these data in an astrophysical context which relates to (i) the threshold photoelectron spectrum which is compared to data relevant to the diffuse interstellar bands (DIBs), (ii) the kinetic photoelectron distribution at the Lyman-α line which is relevant to the dominant heating source in the ISM, and (iii) the absolute photoionization cross section of C60 up to approx. 10.5 eV. The photoelectron spectrum implies that the symmetry of the ground state is different than previous theoretical models have predicted, and this result is discussed in context of recent experimental and theoretical findings. Also presented are partial photoionization cross sections of the first two photoelectron bands and their anisotropy parameters. These data are compared with previous theoretical values and discussed where appropriate.
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Zhang W, Song Y, Liu X, Yan L, Wang Z, Yang Y. Tracking intra-molecular electron and vibrational energy redistribution by time and frequency resolved transient grating spectroscopy. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.07.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Arita R, Koretsune T, Sakai S, Akashi R, Nomura Y, Sano W. Nonempirical Calculation of Superconducting Transition Temperatures in Light-Element Superconductors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29. [PMID: 28060417 DOI: 10.1002/adma.201602421] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/05/2016] [Indexed: 02/05/2023]
Abstract
Recent progress in the fully nonempirical calculation of the superconducting transition temperature (Tc ) is reviewed. Especially, this study focuses on three representative light-element high-Tc superconductors, i.e., elemental Li, sulfur hydrides, and alkali-doped fullerides. Here, it is discussed how crucial it is to develop the beyond Migdal-Eliashberg (ME) methods. For Li, a scheme of superconducting density functional theory for the plasmon mechanism is formulated and it is found that Tc is dramatically enhanced by considering the frequency dependence of the screened Coulomb interaction. For sulfur hydrides, it is essential to go beyond not only the static approximation for the screened Coulomb interaction, but also the constant density-of-states approximation for electrons, the harmonic approximation for phonons, and the Migdal approximation for the electron-phonon vertex, all of which have been employed in the standard ME calculation. It is also shown that the feedback effect in the self-consistent calculation of the self-energy and the zero point motion considerably affect the calculation of Tc . For alkali-doped fullerides, the interplay between electron-phonon coupling and electron correlations becomes more nontrivial. It has been demonstrated that the combination of density functional theory and dynamical mean field theory with the ab initio downfolding scheme for electron-phonon coupled systems works successfully. This study not only reproduces the experimental phase diagram but also obtains a unified view of the high-Tc superconductivity and the Mott-Hubbard transition in the fullerides. The results for these high-Tc superconductors will provide a firm ground for future materials design of new superconductors.
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Affiliation(s)
- Ryotaro Arita
- RIKEN Center for Emergent Matter Science, Wako, Saitama, 351-0198, Japan
- JST ERATO Isobe Degenerate π-Integration Project, Advanced Institute for Materials Research, Tohoku University, Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Takashi Koretsune
- RIKEN Center for Emergent Matter Science, Wako, Saitama, 351-0198, Japan
- JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Shiro Sakai
- RIKEN Center for Emergent Matter Science, Wako, Saitama, 351-0198, Japan
| | - Ryosuke Akashi
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yusuke Nomura
- Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay, F-91128, Palaiseau, France
| | - Wataru Sano
- RIKEN Center for Emergent Matter Science, Wako, Saitama, 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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Burchfield LA, Fahim MA, Wittman RS, Delodovici F, Manini N. Novamene: A new class of carbon allotropes. Heliyon 2017; 3:e00242. [PMID: 28217750 PMCID: PMC5300697 DOI: 10.1016/j.heliyon.2017.e00242] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 12/26/2016] [Accepted: 01/30/2017] [Indexed: 11/27/2022] Open
Abstract
We announce a new class of carbon allotropes. The basis of this new classification resides on the concept of combining hexagonal diamond (sp3 bonded carbon − lonsdaleite) and ring carbon (sp2 bonded carbon − graphene). Since hexagonal diamond acts as an insulator and sp2 bonded rings act as conductors, these predicted materials have potential applications for transistors and other electronic components. We describe the structure of a proposed series of carbon allotropes, novamene, and carry out a detailed computational analysis of the structural and electronic properties of the simplest compound in this class: the single-ring novamene. In addition, we suggest how hundreds of different allotropes of carbon could be constructed within this class.
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Affiliation(s)
| | | | - Richard S Wittman
- Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Francesco Delodovici
- Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
| | - Nicola Manini
- Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
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Nomura Y, Sakai S, Capone M, Arita R. Exotic s-wave superconductivity in alkali-doped fullerides. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:153001. [PMID: 26974650 DOI: 10.1088/0953-8984/28/15/153001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Alkali-doped fullerides (A3C60 with A = K, Rb, Cs) show a surprising phase diagram, in which a high transition-temperature (Tc) s-wave superconducting state emerges next to a Mott insulating phase as a function of the lattice spacing. This is in contrast with the common belief that Mott physics and phonon-driven s-wave superconductivity are incompatible, raising a fundamental question on the mechanism of the high-Tc superconductivity. This article reviews recent ab initio calculations, which have succeeded in reproducing comprehensively the experimental phase diagram with high accuracy and elucidated an unusual cooperation between the electron-phonon coupling and the electron-electron interactions leading to Mott localization to realize an unconventional s-wave superconductivity in the alkali-doped fullerides. A driving force behind the exotic physics is unusual intramolecular interactions, characterized by the coexistence of a strongly repulsive Coulomb interaction and a small effectively negative exchange interaction. This is realized by a subtle energy balance between the coupling with the Jahn-Teller phonons and Hund's coupling within the C60 molecule. The unusual form of the interaction leads to a formation of pairs of up- and down-spin electrons on the molecules, which enables the s-wave pairing. The emergent superconductivity crucially relies on the presence of the Jahn-Teller phonons, but surprisingly benefits from the strong correlations because the correlations suppress the kinetic energy of the electrons and help the formation of the electron pairs, in agreement with previous model calculations. This confirms that the alkali-doped fullerides are a new type of unconventional superconductors, where the unusual synergy between the phonons and Coulomb interactions drives the high-Tc superconductivity.
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Affiliation(s)
- Yusuke Nomura
- Department of Applied Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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Dunn JL, Alqannas HS, Lakin AJ. Jahn–Teller effects and surface interactions in multiply-charged fullerene anions and the effect on scanning tunneling microscopy images. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.05.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Andjelković L, Gruden-Pavlović M, Zlatar M. Density functional theory study of the multimode Jahn–Teller problem in the open-shell corannulenes and coronenes. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Muya JT, Ramanantoanina H, Daul C, Nguyen MT, Gopakumar G, Ceulemans A. Jahn-Teller instability in cationic boron and carbon buckyballs B80+ and C60+: a comparative study. Phys Chem Chem Phys 2013; 15:2829-35. [PMID: 23338939 DOI: 10.1039/c2cp43171h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This paper investigates the Jahn-Teller effect in the icosahedral cation B(80)(+) and compares the descent in symmetry with that in C(60)(+). For both cations the icosahedral ground state is a (2)H(u) state, which exhibits a H ⊗ (g ⊕ 2h) Jahn-Teller instability. A detailed construction of the potential energy surface of B(80)(+) using different DFT methods including B3LYP/6-31G(d), VWN/6-31G(d), PBE/TZP and PBE/6-31G(d) shows that, contrary to C(60)(+), which prefers D(5d) symmetry, the ground state of B(80)(+) adopts S(6) point group symmetry. A D(3d) structure is identified as a saddle point among the S(6) minima of B(80)(+). The distortion of D(3d) to S(6) in B(80)(+) is attributed to a superposition of Jahn-Teller and pseudo-Jahn-Teller effects. Imaginary modes, transforming as the g(g) representation, which are present in neutral icosahedral B(80), form the dominant symmetry breaking active modes. The pronounced difference between the JT effects in the boron and carbon buckyball cations is due to the plasticity of the boron caps. The calculated Jahn-Teller stabilization of B(80)(+) is nearly 1549 cm(-1) (PBE/TZP), which exceeds the stabilization of 596 cm(-1) computed for C(60)(+) at the same level.
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Affiliation(s)
- Jules Tshishimbi Muya
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
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Perić M, Andjelković L, Zlatar M, Nikolić AS, Daul C, Gruden-Pavlović M. Spherical aromaticity of Jahn–Teller active fullerene ions. MONATSHEFTE FUR CHEMIE 2013. [DOI: 10.1007/s00706-013-0943-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Ramanantoanina H, Zlatar M, García-Fernández P, Daul C, Gruden-Pavlović M. General treatment of the multimode Jahn–Teller effect: study of fullerenecations. Phys Chem Chem Phys 2013; 15:1252-9. [DOI: 10.1039/c2cp43591h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Iwahara N, Sato T, Tanaka K. Effect of Coulomb interactions on the vibronic couplings in C60−. J Chem Phys 2012; 136:174315. [DOI: 10.1063/1.4709611] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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Lüders M, Bordoni A, Manini N, Corso AD, Fabrizio M, Tosatti E. Coulomb couplings in positively charged fullerene. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/13642810208220729] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Martin Lüders
- a International School for Advanced Studies , Via Beirut 4, 34014 , Trieste , Italy
- b Istituto Nazionale per la Fisica della Materia Democritos National Simulation Center, and Istituto Nazionale per la Fisica della Materia Unità , Trieste , Italy
| | - Andrea Bordoni
- c Dipartimento Fisica, Università di Milano , Via Celoria 16-20133 Milano, Italy
| | - Nicola Manini
- a International School for Advanced Studies , Via Beirut 4, 34014 , Trieste , Italy
- b Istituto Nazionale per la Fisica della Materia Democritos National Simulation Center, and Istituto Nazionale per la Fisica della Materia Unità , Trieste , Italy
- c Dipartimento Fisica, Università di Milano , Via Celoria 16-20133 Milano, Italy
- d Istituto Nazionale per la Fisica della Materia , Unità di Milano, Milano, Italy
| | - Andrea Dal Corso
- a International School for Advanced Studies , Via Beirut 4, 34014 , Trieste , Italy
- b Istituto Nazionale per la Fisica della Materia Democritos National Simulation Center, and Istituto Nazionale per la Fisica della Materia Unità , Trieste , Italy
| | - Michele Fabrizio
- a International School for Advanced Studies , Via Beirut 4, 34014 , Trieste , Italy
- b Istituto Nazionale per la Fisica della Materia Democritos National Simulation Center, and Istituto Nazionale per la Fisica della Materia Unità , Trieste , Italy
- e International Centre for Theoretical Physics , PO Box 586, 34014, Trieste , Italy
| | - Erio Tosatti
- a International School for Advanced Studies , Via Beirut 4, 34014 , Trieste , Italy
- b Istituto Nazionale per la Fisica della Materia Democritos National Simulation Center, and Istituto Nazionale per la Fisica della Materia Unità , Trieste , Italy
- e International Centre for Theoretical Physics , PO Box 586, 34014, Trieste , Italy
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Vibronic Coupling Constant and Vibronic Coupling Density. SPRINGER SERIES IN CHEMICAL PHYSICS 2009. [DOI: 10.1007/978-3-642-03432-9_5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Tóbik J, Tosatti E. Structure, Vibrations and Raman Modes in Electron Doped Metal Phthalocyanines. J Phys Chem A 2007; 111:12570-6. [DOI: 10.1021/jp075944q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jaroslav Tóbik
- International School for Advanced Studies (SISSA), and INFM Democritos National Simulation Center, Via Beirut 2-4, I-34014 Trieste, Italy, and The Abdus Salam International Centre for Theoretical Physics (ICTP), P.O. Box 586, I-34014 Trieste, Italy
| | - Erio Tosatti
- International School for Advanced Studies (SISSA), and INFM Democritos National Simulation Center, Via Beirut 2-4, I-34014 Trieste, Italy, and The Abdus Salam International Centre for Theoretical Physics (ICTP), P.O. Box 586, I-34014 Trieste, Italy
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Chibotaru L. Spin–vibronic superexchange and dynamical vibronic order in ammoniated cubic fullerides. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2006.12.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Bersuker I. The Jahn–Teller effect as a general tool for solving molecular and solid state problems: Novel findings. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2006.12.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sato T, Ceulemans A. Vibronic and spin-orbit coupling of a d9 transition-metal ion encapsulated in an icosahedral cage: The (Γ8+Γ9)×(g+2h) Jahn-Teller problem. J Chem Phys 2007; 126:184501. [PMID: 17508805 DOI: 10.1063/1.2730504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Interplay between the vibronic and spin-orbit coupling in the (Gamma8+Gamma9)x(g+2h) Jahn-Teller problem, where Gamma8 and Gamma9 are the quartet and sextet spin representation, and g and h denote the fourfold and fivefold degenerate vibrational modes in icosahedral symmetry, respectively, is studied. A 4d9 or 5d9 transition-metal ion in an icosahedral field may provide a realization of this system.
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Affiliation(s)
- Tohru Sato
- Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 34-4, Sakyo-ku, Kyoto 606-8103, Japan.
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Garcia-Fernandez P, Bersuker IB, Boggs JE. Orbital disproportionation and spin crossover as a pseudo Jahn-Teller effect. J Chem Phys 2006; 125:104102. [PMID: 16999510 DOI: 10.1063/1.2346682] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
It is shown that in systems with electronic half-closed-shell configurations of degenerate orbitals, e(2) and t(3) (which have totally symmetric charge distribution), ground state distortions from high-symmetry geometries may occur due to a strong pseudo Jahn-Teller effect (PJTE) in the excited states, resulting also in a novel phenomenon of PJT-induced spin crossover. There is no JTE neither in the ground state term nor in the excited terms (including degenerate terms) of these configurations but a strong PJT mixing between two excited states [((1)E+(1)A) [cross-filled circle] e and ((2)T(1)+(2)T(2)) [cross-filled circle] e in the e(2) and t(3) cases, respectively] pushes down the lower term to cross the ground state of the undistorted system and to form the global minimum with a distorted geometry. The analysis of the electronic structure of this distorted configuration shows that it is accompanied by orbital disproportionation: instead of proportional population of all degenerate orbitals by one electron each (as in the ground state of the undistorted system that follows Hund's rule), two electrons with opposite spins occupy one orbital, resulting in transformations of the type (e(theta);e(epsilon))-->(e(theta)e(theta)) for e(2) and (t(x);t(y);t(z))-->(t(x);t(x);t(z)) for t(3) systems. Since the two geometry configurations, undistorted and distorted, appertain to different electronic terms that have different spin states, the formation of the global minimum with the distorted configuration is accompanied by a spin crossover. Distinguished from the known spin-crossover phenomenon in some transition metal compounds, the two states with different spin in the PJT-induced spin crossover have also different nuclear configurations, undistorted and distorted, that coexist with a relatively small energy difference. The change of configuration reduces significantly the rate of relaxation between the two states; the relaxation is further reduced by the lower spin-orbital coupling in the light-atom systems as compared with transition metal compounds. This means that there may be systems for which the switch between the two states (in both directions) under perturbations may be observed as a single-molecule phenomenon. Systems with half-closed-shell electronic configurations e(2) and t(3) are available in a variety of molecules from different classes, organic and inorganic; the theory is illustrated here by ab initio calculations for a series of molecular systems, including Si(3), Si(3)C, CuF(3), Na(3), Si(4), Na(4), Na(4) (-), and C(60) (3-), which are in agreement with the experimental data available.
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Affiliation(s)
- P Garcia-Fernandez
- Institute for Theoretical Chemistry, Chemistry and Biochemistry Department, The University of Texas at Austin, Austin, TX 78712-0165, USA.
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Berrah N, Bozek J, Bilodeau R, Kukk E. Studies of complex systems: from atoms to clusters. Radiat Phys Chem Oxf Engl 1993 2004. [DOI: 10.1016/j.radphyschem.2003.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Manini N, Gattari P, Tosatti E. Jahn-Teller spectral fingerprint in molecular photoemission: c60. PHYSICAL REVIEW LETTERS 2003; 91:196402. [PMID: 14611594 DOI: 10.1103/physrevlett.91.196402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2003] [Indexed: 05/24/2023]
Abstract
The h(u) hole spectral intensity for C60-->C+60 molecular photoemission is calculated at finite temperature by a parameter-free Lanczos diagonalization of the electron-vibration Hamiltonian, including the full 8 H(g), 6 G(g), and 2 A(g) mode couplings. The computed spectrum at 800 K is in striking agreement with gas-phase data. The energy separation of the first main shoulder from the main photoemission peak, 230 meV in C60, is shown to measure directly and rather generally the strength of the final-state Jahn-Teller coupling.
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Affiliation(s)
- Nicola Manini
- Dipartimento di Fisica, Università di Milano, Via Celoria 16, 20133 Milan, Italy.
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Manini N, Tosatti E. Comment on "experimental evidence of a dynamic Jahn-Teller effect in C(+60"). PHYSICAL REVIEW LETTERS 2003; 90:249601-249602. [PMID: 12857234 DOI: 10.1103/physrevlett.90.249601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2003] [Indexed: 05/24/2023]
Affiliation(s)
- Nicola Manini
- Dipartimento di Fisica, Università di MilanoVia Celoria 16, 20133 Milano, Italy
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Lüders M, Manini N. Jahn–Teller Distortions and Excitation Energies in. ADVANCES IN QUANTUM CHEMISTRY 2003. [DOI: 10.1016/s0065-3276(03)44018-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Canton SE, Yencha AJ, Kukk E, Bozek JD, Lopes MCA, Snell G, Berrah N. Experimental evidence of a dynamic Jahn-Teller effect in C60(+). PHYSICAL REVIEW LETTERS 2002; 89:045502. [PMID: 12144488 DOI: 10.1103/physrevlett.89.045502] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2002] [Indexed: 05/23/2023]
Abstract
Detailed analysis of the highest occupied molecular orbital band shape in the photoelectron spectrum of gaseous C60 reveals a dynamic Jahn-Teller effect in the ground state of C60(+). The direct observation of three tunneling states asserts a D(3d) geometry for the isolated cation, originating from a strong vibronic coupling. These results show that the ionic motion plays an important role in the electron-phonon interaction.
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Affiliation(s)
- S E Canton
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA.
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Abstract
High-temperature superconductivity in doped Mott insulators such as the cuprates contradicts the conventional wisdom that electron repulsion is detrimental to superconductivity. Because doped fullerene conductors are also strongly correlated, the recent discovery of high-critical-temperature, presumably s-wave, superconductivity in C60 field effect devices is even more puzzling. We examine a dynamical mean-field solution of a model for electron-doped fullerenes that shows how strong correlations can indeed enhance superconductivity close to the Mott transition. We argue that the mechanism responsible for this enhancement could be common to a wider class of strongly correlated models, including those for cuprate superconductors.
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Affiliation(s)
- M Capone
- Istituto Nazionale per la Fisica della Materia (INFM) Center for Statistical Mechanics and Complexity and Physics Department University of Rome "La Sapienza" Piazzale A. Moro, 2, I-00185, Rome, Italy.
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