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Gotter R, Verna A, Sbroscia M, Moroni R, Bisio F, Iacobucci S, Offi F, Vaidya SR, Ruocco A, Stefani G. Unexpectedly Large Electron Correlation Measured in Auger Spectra of Ferromagnetic Iron Thin Films: Orbital-Selected Coulomb and Exchange Contributions. PHYSICAL REVIEW LETTERS 2020; 125:067202. [PMID: 32845695 DOI: 10.1103/physrevlett.125.067202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
A set of electron-correlation energies as large as 10 eV have been measured for a magnetic 2 ML Fe film deposited on Ag(001). By exploiting the spin selectivity in angle-resolved Auger-photoelectron coincidence spectroscopy and the Cini-Sawatzky theory, the core-valence-valence Auger spectrum of a spin-polarized system have been resolved: correlation energies have been determined for each individual combination of the two holes created in the four subbands involved in the decay: majority and minority spin, as well as e_{g} and t_{2g}. The energy difference between final states with parallel and antiparallel spin of the two emitted electrons is ascribed to the spin-flip energy for the final ion state, thus disentangling the contributions of Coulomb and exchange interactions.
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Affiliation(s)
- R Gotter
- CNR-IOM, Istituto Officina dei Materiali, c/o Area Science Park, SS14 km 163,5 I-34149 Basovizza-Trieste, Italy
| | - A Verna
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy
| | - M Sbroscia
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy
| | - R Moroni
- CNR-SPIN, Corso Perrone 24, I-16152 Genova, Italy
| | - F Bisio
- CNR-SPIN, Corso Perrone 24, I-16152 Genova, Italy
| | - S Iacobucci
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy
- CNR-ISM, Via Fosso del Cavaliere 100, 00133 Roma, Italy
| | - F Offi
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy
| | - S R Vaidya
- CNR-IOM, Istituto Officina dei Materiali, c/o Area Science Park, SS14 km 163,5 I-34149 Basovizza-Trieste, Italy
- Scuola di Dottorato in Nanotecnologie, Università di Trieste, Piazzale Europa 1, I-34127 Trieste, Italy
| | - A Ruocco
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy
| | - G Stefani
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Rome, Italy
- CNR-ISM, Via Fosso del Cavaliere 100, 00133 Roma, Italy
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Rausch R, Potthoff M, Kawakami N. Magnetic Doublon Bound States in the Kondo Lattice Model. PHYSICAL REVIEW LETTERS 2019; 123:216401. [PMID: 31809148 DOI: 10.1103/physrevlett.123.216401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Indexed: 06/10/2023]
Abstract
We present a novel pairing mechanism for electrons, mediated by magnons. These paired bound states are termed "magnetic doublons." Applying numerically exact techniques (full diagonalization and the density-matrix renormalization group, DMRG) to the Kondo lattice model at strong exchange coupling J for different fillings and magnetic configurations, we demonstrate that magnetic doublon excitations exist as composite objects with very weak dispersion. They are highly stable, support a novel "inverse" colossal magnetoresistance and potentially other effects.
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Affiliation(s)
- Roman Rausch
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Michael Potthoff
- Department of Physics, University of Hamburg, Jungiusstraße 9, D-20355 Hamburg, Germany
| | - Norio Kawakami
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
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FUKUDA Y. Appearance Potential Spectroscopy (APS): Old Method, but Applicable to Study of Nano-structures. ANAL SCI 2010; 26:187-97. [DOI: 10.2116/analsci.26.187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Y. FUKUDA
- Research Institute of Electronics, Shizuoka University
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Seibold G, Becca F, Lorenzana J. Theory of antibound states in partially filled narrow band systems. PHYSICAL REVIEW LETTERS 2008; 100:016405. [PMID: 18232796 DOI: 10.1103/physrevlett.100.016405] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Indexed: 05/25/2023]
Abstract
We present a theory of the dynamical two-particle response function in the Hubbard model based on the time-dependent Gutzwiller approximation. The results are in excellent agreement with exact diagonalization on small clusters and are reliable even for high densities, where the usual ladder approximation breaks down. We apply the theory to the computation of antibound states relevant for Auger spectroscopy and cold atom physics.
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Affiliation(s)
- G Seibold
- Institut für Physik, BTU Cottbus, P.O. Box 101344, 03013 Cottbus, Germany
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