1
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Chen QY, Xu DF, Niu XH, Peng R, Xu HC, Wen CHP, Liu X, Shu L, Tan SY, Lai XC, Zhang YJ, Lee H, Strocov VN, Bisti F, Dudin P, Zhu JX, Yuan HQ, Kirchner S, Feng DL. Band Dependent Interlayer f-Electron Hybridization in CeRhIn_{5}. Phys Rev Lett 2018; 120:066403. [PMID: 29481263 DOI: 10.1103/physrevlett.120.066403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 01/02/2018] [Indexed: 06/08/2023]
Abstract
A key issue in heavy fermion research is how subtle changes in the hybridization between the 4f (5f) and conduction electrons can result in fundamentally different ground states. CeRhIn_{5} stands out as a particularly notable example: when replacing Rh with either Co or Ir, antiferromagnetism gives way to superconductivity. In this photoemission study of CeRhIn_{5}, we demonstrate that the use of resonant angle-resolved photoemission spectroscopy with polarized light allows us to extract detailed information on the 4f crystal field states and details on the 4f and conduction electron hybridization, which together determine the ground state. We directly observe weakly dispersive Kondo resonances of f electrons and identify two of the three Ce 4f_{5/2}^{1} crystal-electric-field levels and band-dependent hybridization, which signals that the hybridization occurs primarily between the Ce 4f states in the CeIn_{3} layer and two more three-dimensional bands composed of the Rh 4d and In 5p orbitals in the RhIn_{2} layer. Our results allow us to connect the properties observed at elevated temperatures with the unusual low-temperature properties of this enigmatic heavy fermion compound.
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Affiliation(s)
- Q Y Chen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621908, China
| | - D F Xu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - X H Niu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - R Peng
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - H C Xu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - C H P Wen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - X Liu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - L Shu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - S Y Tan
- Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621908, China
| | - X C Lai
- Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621908, China
| | - Y J Zhang
- Center for Correlated Matter, Zhejiang University, Hangzhou 310058, China
- Department of Physics, Zhejiang University, Hangzhou 310027, China
| | - H Lee
- Center for Correlated Matter, Zhejiang University, Hangzhou 310058, China
| | - V N Strocov
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - F Bisti
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - P Dudin
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - J-X Zhu
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - H Q Yuan
- Center for Correlated Matter, Zhejiang University, Hangzhou 310058, China
- Department of Physics, Zhejiang University, Hangzhou 310027, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - S Kirchner
- Center for Correlated Matter, Zhejiang University, Hangzhou 310058, China
| | - D L Feng
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
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2
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Xu N, Autès G, Matt CE, Lv BQ, Yao MY, Bisti F, Strocov VN, Gawryluk D, Pomjakushina E, Conder K, Plumb NC, Radovic M, Qian T, Yazyev OV, Mesot J, Ding H, Shi M. Distinct Evolutions of Weyl Fermion Quasiparticles and Fermi Arcs with Bulk Band Topology in Weyl Semimetals. Phys Rev Lett 2017; 118:106406. [PMID: 28339253 DOI: 10.1103/physrevlett.118.106406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Indexed: 06/06/2023]
Abstract
The Weyl semimetal phase is a recently discovered topological quantum state of matter characterized by the presence of topologically protected degeneracies near the Fermi level. These degeneracies are the source of exotic phenomena, including the realization of chiral Weyl fermions as quasiparticles in the bulk and the formation of Fermi arc states on the surfaces. Here, we demonstrate that these two key signatures show distinct evolutions with the bulk band topology by performing angle-resolved photoemission spectroscopy, supported by first-principles calculations, on transition-metal monophosphides. While Weyl fermion quasiparticles exist only when the chemical potential is located between two saddle points of the Weyl cone features, the Fermi arc states extend in a larger energy scale and are robust across the bulk Lifshitz transitions associated with the recombination of two nontrivial Fermi surfaces enclosing one Weyl point into a single trivial Fermi surface enclosing two Weyl points of opposite chirality. Therefore, in some systems (e.g., NbP), topological Fermi arc states are preserved even if Weyl fermion quasiparticles are absent in the bulk. Our findings not only provide insight into the relationship between the exotic physical phenomena and the intrinsic bulk band topology in Weyl semimetals, but also resolve the apparent puzzle of the different magnetotransport properties observed in TaAs, TaP, and NbP, where the Fermi arc states are similar.
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Affiliation(s)
- N Xu
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - G Autès
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials MARVEL, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - C E Matt
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - B Q Lv
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - M Y Yao
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - F Bisti
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - V N Strocov
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - D Gawryluk
- Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - E Pomjakushina
- Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - K Conder
- Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Radovic
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - T Qian
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - O V Yazyev
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials MARVEL, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - J Mesot
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Laboratory for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - H Ding
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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3
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Manzoni G, Gragnaniello L, Autès G, Kuhn T, Sterzi A, Cilento F, Zacchigna M, Enenkel V, Vobornik I, Barba L, Bisti F, Bugnon P, Magrez A, Strocov VN, Berger H, Yazyev OV, Fonin M, Parmigiani F, Crepaldi A. Evidence for a Strong Topological Insulator Phase in ZrTe_{5}. Phys Rev Lett 2016; 117:237601. [PMID: 27982645 DOI: 10.1103/physrevlett.117.237601] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Indexed: 05/05/2023]
Abstract
The complex electronic properties of ZrTe_{5} have recently stimulated in-depth investigations that assigned this material to either a topological insulator or a 3D Dirac semimetal phase. Here we report a comprehensive experimental and theoretical study of both electronic and structural properties of ZrTe_{5}, revealing that the bulk material is a strong topological insulator (STI). By means of angle-resolved photoelectron spectroscopy, we identify at the top of the valence band both a surface and a bulk state. The dispersion of these bands is well captured by ab initio calculations for the STI case, for the specific interlayer distance measured in our x-ray diffraction study. Furthermore, these findings are supported by scanning tunneling spectroscopy revealing the metallic character of the sample surface, thus confirming the strong topological nature of ZrTe_{5}.
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Affiliation(s)
- G Manzoni
- Universitá degli Studi di Trieste, Via Alfonso Valerio 2, Trieste 34127, Italy
| | - L Gragnaniello
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - G Autès
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials MARVEL, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - T Kuhn
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - A Sterzi
- Universitá degli Studi di Trieste, Via Alfonso Valerio 2, Trieste 34127, Italy
| | - F Cilento
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste I-34149, Italy
| | - M Zacchigna
- Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park - Basovizza, I-34149 Trieste, Italy
| | - V Enenkel
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - I Vobornik
- Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park - Basovizza, I-34149 Trieste, Italy
| | - L Barba
- Institute of Crystallography, CNR, Area Science Park, Strada Statale 14, km 163.5 Trieste I-34149, Italy
| | - F Bisti
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Ph Bugnon
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - A Magrez
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - V N Strocov
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - H Berger
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - O V Yazyev
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials MARVEL, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - M Fonin
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - F Parmigiani
- Universitá degli Studi di Trieste, Via Alfonso Valerio 2, Trieste 34127, Italy
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste I-34149, Italy
- International Faculty, University of Köln, 50937 Köln, Germany
| | - A Crepaldi
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste I-34149, Italy
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4
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Krempaský J, Muff S, Bisti F, Fanciulli M, Volfová H, Weber AP, Pilet N, Warnicke P, Ebert H, Braun J, Bertran F, Volobuev VV, Minár J, Springholz G, Dil JH, Strocov VN. Entanglement and manipulation of the magnetic and spin-orbit order in multiferroic Rashba semiconductors. Nat Commun 2016; 7:13071. [PMID: 27767052 PMCID: PMC5078730 DOI: 10.1038/ncomms13071] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/31/2016] [Indexed: 11/17/2022] Open
Abstract
Entanglement of the spin–orbit and magnetic order in multiferroic materials bears a strong potential for engineering novel electronic and spintronic devices. Here, we explore the electron and spin structure of ferroelectric α-GeTe thin films doped with ferromagnetic Mn impurities to achieve its multiferroic functionality. We use bulk-sensitive soft-X-ray angle-resolved photoemission spectroscopy (SX-ARPES) to follow hybridization of the GeTe valence band with the Mn dopants. We observe a gradual opening of the Zeeman gap in the bulk Rashba bands around the Dirac point with increase of the Mn concentration, indicative of the ferromagnetic order, at persistent Rashba splitting. Furthermore, subtle details regarding the spin–orbit and magnetic order entanglement are deduced from spin-resolved ARPES measurements. We identify antiparallel orientation of the ferroelectric and ferromagnetic polarization, and altering of the Rashba-type spin helicity by magnetic switching. Our experimental results are supported by first-principles calculations of the electron and spin structure. In α-GeTe, ferroelectric polarization acts to break inversion symmetry of the lattice and induce a strong Rashba-type spin splitting of the electronic band structure. Here, the authors study how this effect competes with Zeeman splitting due to ferromagnetic exchange coupling in Mn-doped GeTe.
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Affiliation(s)
- J Krempaský
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - S Muff
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.,Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - F Bisti
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Fanciulli
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.,Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - H Volfová
- Department of Chemistry, Ludwig Maximillian University, 81377 Munich, Germany
| | - A P Weber
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.,Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - N Pilet
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - P Warnicke
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - H Ebert
- Department of Chemistry, Ludwig Maximillian University, 81377 Munich, Germany
| | - J Braun
- Department of Chemistry, Ludwig Maximillian University, 81377 Munich, Germany
| | - F Bertran
- SOLEIL Synchrotron, L'Orme des Merisiers, F-91192 Gif-sur-Yvette, France
| | - V V Volobuev
- National Technical University, Kharkiv Polytechnic Institute, Frunze Str. 21, 61002 Kharkiv, Ukraine.,Institut für Halbleiter-und Festkörperphysik, Johannes Kepler Universität, A-4040 Linz, Austria
| | - J Minár
- Department of Chemistry, Ludwig Maximillian University, 81377 Munich, Germany.,New Technologies-Research Center University of West Bohemia, Plzeň, Czech Republic
| | - G Springholz
- Institut für Halbleiter-und Festkörperphysik, Johannes Kepler Universität, A-4040 Linz, Austria
| | - J H Dil
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.,Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - V N Strocov
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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5
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Matt CE, Xu N, Lv B, Ma J, Bisti F, Park J, Shang T, Cao C, Song Y, Nevidomskyy AH, Dai P, Patthey L, Plumb NC, Radovic M, Mesot J, Shi M. NaFe_{0.56}Cu_{0.44}As: A Pnictide Insulating Phase Induced by On-Site Coulomb Interaction. Phys Rev Lett 2016; 117:097001. [PMID: 27610876 DOI: 10.1103/physrevlett.117.097001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Indexed: 06/06/2023]
Abstract
In the studies of iron pnictides, a key question is whether their bad-metal state from which the superconductivity emerges lies in close proximity with a magnetically ordered insulating phase. Recently, it was found that at low temperatures, the heavily Cu-doped NaFe_{1-x}Cu_{x}As (x>0.3) iron pnictide is an insulator with long-range antiferromagnetic order, similar to the parent compound of cuprates but distinct from all other iron pnictides. Using angle-resolved photoemission spectroscopy, we determined the momentum-resolved electronic structure of NaFe_{1-x}Cu_{x}As (x=0.44) and identified that its ground state is a narrow-gap insulator. Combining the experimental results with density functional theory (DFT) and DFT+U calculations, our analysis reveals that the on-site Coulombic (Hubbard) and Hund's coupling energies play crucial roles in the formation of the band gap about the chemical potential. We propose that at finite temperatures, charge carriers are thermally excited from the Cu-As-like valence band into the conduction band, which is of Fe 3d-like character. With increasing temperature, the number of electrons in the conduction band becomes larger and the hopping energy between Fe sites increases, and finally the long-range antiferromagnetic order is destroyed at T>T_{N}. Our study provides a basis for investigating the evolution of the electronic structure of a Mott insulator transforming into a bad metallic phase and eventually forming a superconducting state in iron pnictides.
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Affiliation(s)
- C E Matt
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Laboratory for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - N Xu
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne, CH-10 15 Lausanne, Switzerland
| | - Baiqing Lv
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Junzhang Ma
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - F Bisti
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - J Park
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - T Shang
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne, CH-10 15 Lausanne, Switzerland
- Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Chongde Cao
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
- Department of Applied Physics, Northwestern Polytechnical University, Xian 710072, China
| | - Yu Song
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | | | - Pengcheng Dai
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
| | - L Patthey
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Radovic
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - J Mesot
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Laboratory for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
- Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne, CH-10 15 Lausanne, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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6
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Rogalev VA, Gröning O, Widmer R, Dil JH, Bisti F, Lev LL, Schmitt T, Strocov VN. Fermi states and anisotropy of Brillouin zone scattering in the decagonal Al-Ni-Co quasicrystal. Nat Commun 2015; 6:8607. [PMID: 26443439 PMCID: PMC4633949 DOI: 10.1038/ncomms9607] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 09/10/2015] [Indexed: 11/08/2022] Open
Abstract
Quasicrystals (QCs) are intermetallic alloys that have excellent long-range order but lack translational symmetry in at least one dimension. The valence band electronic structure near the Fermi energy EF in such materials is of special interest since it has a direct relation to their unusual physical properties. However, the Fermi surface (FS) topology as well as the mechanism of QC structure stabilization are still under debate. Here we report the first observation of the three-dimensional FS and valence band dispersions near EF in decagonal Al70Ni20Co10 (d-AlNiCo) QCs using soft X-ray angle-resolved photoemission spectroscopy. We show that the FS, formed by dispersive Al sp-states, has a multicomponent character due to a large contribution from high-order bands. Moreover, we discover that the magnitude of the gap at the FS related to the interaction with Brillouin zone boundary (Hume-Rothery gap) critically differs for the periodic and quasiperiodic directions.
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Affiliation(s)
- V. A. Rogalev
- Department for Synchrotron Radiation and Nanotechnology (SYN), Swiss Light Source, Paul Scherrer Institute, Villigen CH-5232, Switzerland
| | - O. Gröning
- Department of Advanced Materials and Surfaces, EMPA, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf CH-8600, Switzerland
| | - R. Widmer
- Department of Advanced Materials and Surfaces, EMPA, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf CH-8600, Switzerland
| | - J. H. Dil
- Department for Synchrotron Radiation and Nanotechnology (SYN), Swiss Light Source, Paul Scherrer Institute, Villigen CH-5232, Switzerland
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - F. Bisti
- Department for Synchrotron Radiation and Nanotechnology (SYN), Swiss Light Source, Paul Scherrer Institute, Villigen CH-5232, Switzerland
| | - L. L. Lev
- Department for Synchrotron Radiation and Nanotechnology (SYN), Swiss Light Source, Paul Scherrer Institute, Villigen CH-5232, Switzerland
- National Research Center Kurchatov Institute, Akademika Kurchatova Square 1, Moscow 123182, Russia
| | - T. Schmitt
- Department for Synchrotron Radiation and Nanotechnology (SYN), Swiss Light Source, Paul Scherrer Institute, Villigen CH-5232, Switzerland
| | - V. N. Strocov
- Department for Synchrotron Radiation and Nanotechnology (SYN), Swiss Light Source, Paul Scherrer Institute, Villigen CH-5232, Switzerland
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7
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Donarelli M, Perrozzi F, Bisti F, Paparella F, Feyer V, Ponzoni A, Gonchigsuren M, Ottaviano L. Few layered MoS2 lithography with an AFM tip: description of the technique and nanospectroscopy investigations. Nanoscale 2015; 7:11453-11459. [PMID: 26083804 DOI: 10.1039/c5nr02337h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A novel technique to lithograph the MoS2 surface is described here. Mechanically exfoliated MoS2 flakes have been patterned with an atomic force microscope tip. After the patterning process, the lithographed areas have been removed by selective chemical etching. The electronic properties of the MoS2 flakes have been analyzed with spatially resolved photoelectron spectroscopy, with tunable incident photon energy, provided by a synchrotron light source. Tens of meV core level shifts can be recorded in relation to the flakes edges, coming from both the exfoliation and from the lithography.
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Affiliation(s)
- M Donarelli
- Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio 10, 67100, L'Aquila, Italy.
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8
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Bisti F, Stroppa A, Perrozzi F, Donarelli M, Picozzi S, Coreno M, de Simone M, Prince KC, Ottaviano L. The electronic structure of gas phase croconic acid compared to the condensed phase: More insight into the hydrogen bond interaction. J Chem Phys 2013; 138:014308. [DOI: 10.1063/1.4773059] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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9
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Bisti F, Stroppa A, Donarelli M, Anemone G, Perrozzi F, Picozzi S, Ottaviano L. Unravelling the role of the central metal ion in the electronic structure of tris(8-hydroxyquinoline) metal chelates: photoemission spectroscopy and hybrid functional calculations. J Phys Chem A 2012; 116:11548-52. [PMID: 23106099 DOI: 10.1021/jp308303d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic structures of tris(8-hydroxyquinolinato)-erbium(III) (ErQ(3)) and tris(8-hydroxyquinolinato)-aluminum(III) (AlQ(3)) have been studied by means of core level and valence band photoemission spectroscopy with the theoretical support of hybrid Heyd-Scuseria-Ernzerhof density functional theory, to investigate the role played by the central metal atom. A lower binding energy (0.2 eV and 0.3 eV, respectively) of the O 1s and N 1s core levels has been observed for ErQ(3) with respect to AlQ(3). Differences in the valence band spectra, mainly related to the first two peaks next to the highest occupied molecular orbital (HOMO), have been ascribed to an energetic shift (to 0.4 eV lower energies for ErQ(3)) of the σ molecular orbital between the oxygen atoms and the central metal atom. A lower (by 0.5 eV) ionization energy has been measured for the ErQ(3). The interpretation of these results is based on a reduced interaction between the central metal atom and the ligands in ErQ(3), with increased electronic charge around the ligands, due to the higher ionic radius and the lower electronegativity of Er with respect to Al.
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Affiliation(s)
- F Bisti
- Dipartimento di Scienze Fisiche e Chimiche, Università dell'Aquila, Via Vetoio, 67100 L'Aquila, Italy.
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Prezioso S, Perrozzi F, Donarelli M, Bisti F, Santucci S, Palladino L, Nardone M, Treossi E, Palermo V, Ottaviano L. Large area extreme-UV lithography of graphene oxide via spatially resolved photoreduction. Langmuir 2012; 28:5489-5495. [PMID: 22375596 DOI: 10.1021/la204637a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The ability to pattern graphene over large areas with nanometer resolution is the current request for nanodevice fabrication at the industrial scale. Existing methods do not match high throughput with nanometer resolution. We propose a high-throughput resistless extreme-UV (EUV) photolithographic approach operating with sub-micrometer resolution on large area (~10 mm(2)) graphene oxide (GO) films via spatially resolved photoreduction. The efficiency of EUV photoreduction is tested with 46.9 nm coherent light produced by a table top capillary discharge plasma source. Irradiated samples are studied by X-ray photoemission spectroscopy (XPS) and micro-Raman Spectroscopy (μRS). XPS data show that 200 mJ/cm(2) EUV dose produces, onto pristine GO, a 6% increase of sp(2) carbon bonds and a 20% decrease of C-O bonds. μRS data demonstrate a photoreduction efficiency 2 orders of magnitude higher than the one reported in the literature for UV-assisted photoreduction. GO patterning is obtained modulating the EUV dose with a Lloyd's interferometer. The lithographic features consist of GO stripes with modulated reduction degree. Such modulation is investigated and demonstrated by μRS on patterns with 2 μm periodicity.
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Affiliation(s)
- S Prezioso
- Dipartimento di Fisica, Università dell'Aquila, Via Vetoio, 67100, L'Aquila, Italy.
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Bisti F, Stroppa A, Picozzi S, Ottaviano L. Fingerprints of the hydrogen bond in the photoemission spectra of croconic acid condensed phase: An x-ray photoelectron spectroscopy and ab-initio study. J Chem Phys 2011; 134:174505. [DOI: 10.1063/1.3586813] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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De Marco P, Fioriti F, Bisti F, Parisse P, Santucci S, Ottaviano L. Bulk phase two dimensional chiral growth of 6, 13 Pentacenequinone on SiO2. Journal of Applied Physics 2011. [DOI: 10.1063/1.3549833] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Ottaviano L, Kwoka M, Bisti F, Parisse P, Grossi V, Santucci S, Szuber J. Local surface morphology and chemistry of SnO2 thin films deposited by rheotaxial growth and thermal oxidation method for gas sensor application. Thin Solid Films 2009. [DOI: 10.1016/j.tsf.2009.04.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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