1
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Zhang Y, Giménez-Santamarina S, Cardona-Serra S, Gao F, Coronado E, Brandbyge M. Strong Electron-Vibration Signals in Weakly Coupled Molecular Junctions: Activation of Spin-Crossover. NANO LETTERS 2024; 24:9846-9853. [PMID: 39092593 DOI: 10.1021/acs.nanolett.4c01684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Manipulating individual molecular spin states with electronic current has the potential to revolutionize quantum information devices. However, it is still unclear how a current can cause a spin transition in single-molecule devices. Here, we propose a spin-crossover (SCO) mechanism induced by electron-phonon coupling in an iron(II) phthalocyanine molecule situated on a graphene-decoupled Ir(111) substrate. We performed simulations of both elastic and inelastic electron tunneling spectroscopy (IETS), which reveal current-induced Fe-N vibrations and an underestimation of established electron-vibration signals. Going beyond standard perturbation theory, we examined molecules in various charge and spin states using the Franck-Condon framework. The increased probability of spin switching suggests that notable IETS signals indicate SCO triggered by the inelastic vibrational excitation associated with Fe-N stretching.
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Affiliation(s)
- Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | | | | | - Fei Gao
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, 46980 Paterna, Spain
| | - Mads Brandbyge
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
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2
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Gao Y, Vlaic S, Gorni T, De' Medici L, Clair S, Roditchev D, Pons S. Manipulation of the Magnetic State of a Porphyrin-Based Molecule on Gold: From Kondo to Quantum Nanomagnet via the Charge Fluctuation Regime. ACS NANO 2023; 17:9082-9089. [PMID: 37162317 DOI: 10.1021/acsnano.2c12223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
By moving individual Fe-porphyrin-based molecules with the tip of a scanning tunneling microscope in the vicinity of the elbow of the herringbone-reconstructed Au(111) containing a Br atom, we reversibly and continuously control their magnetic state. Several regimes are obtained experimentally and explored theoretically: from the integer spin limit, through intermediate magnetic states with renormalized magnetic anisotropy, until the Kondo-screened regime, corresponding to a progressive increase of charge fluctuations and mixed valency due to an increase in the interaction of the molecular Fe states with the substrate Fermi sea. Our study demonstrates the potential of utilizing charge fluctuations to generate and tune quantum magnetic states in molecule-surface hybrids.
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Affiliation(s)
- Yingzheng Gao
- Laboratoire de Physique et d'Étude des Matériaux (LPEM), ESPCI Paris, PSL Research University, CNRS UMR8213, Sorbonne Université, 75005 Paris, France
| | - Sergio Vlaic
- Laboratoire de Physique et d'Étude des Matériaux (LPEM), ESPCI Paris, PSL Research University, CNRS UMR8213, Sorbonne Université, 75005 Paris, France
| | - Tommaso Gorni
- Laboratoire de Physique et d'Étude des Matériaux (LPEM), ESPCI Paris, PSL Research University, CNRS UMR8213, Sorbonne Université, 75005 Paris, France
| | - Luca De' Medici
- Laboratoire de Physique et d'Étude des Matériaux (LPEM), ESPCI Paris, PSL Research University, CNRS UMR8213, Sorbonne Université, 75005 Paris, France
| | - Sylvain Clair
- Aix Marseille University, CNRS, IM2NP, 13397 Marseille, France
| | - Dimitri Roditchev
- Laboratoire de Physique et d'Étude des Matériaux (LPEM), ESPCI Paris, PSL Research University, CNRS UMR8213, Sorbonne Université, 75005 Paris, France
- Institut des Nanosciences de Paris, Sorbonne Université, CNRS UMR7588, 75005 Paris, France
| | - Stéphane Pons
- Laboratoire de Physique et d'Étude des Matériaux (LPEM), ESPCI Paris, PSL Research University, CNRS UMR8213, Sorbonne Université, 75005 Paris, France
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3
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Meng X, Möller J, Mansouri M, Sánchez-Portal D, Garcia-Lekue A, Weismann A, Li C, Herges R, Berndt R. Controlling the Spin States of FeTBrPP on Au(111). ACS NANO 2022; 17:1268-1274. [PMID: 36440841 DOI: 10.1021/acsnano.2c09310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Spin-flip excitations of iron porphyrin molecules on Au(111) are investigated with a low-temperature scanning tunneling microscope. The molecules adopt two distinct adsorption configurations on the surface that exhibit different magnetic anisotropy energies. Density functional theory calculations show that the different structures and excitation energies reflect unlike occupations of the Fe 3d levels. We demonstrate that the magnetic anisotropy energy can be controlled by changing the adsorption site, the orientation, or the tip-molecule distance.
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Affiliation(s)
- Xiangzhi Meng
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Jenny Möller
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Masoud Mansouri
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU, 20018Donostia-San Sebastián, Spain
| | - Daniel Sánchez-Portal
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Centro de Física de Materiales CSIC-UPV/EHU, 20018Donostia-San Sebastián, Spain
| | - Aran Garcia-Lekue
- Donostia International Physics Center (DIPC), 20018Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013Bilbao, Spain
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Chao Li
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, 24098Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098Kiel, Germany
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4
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Gao F, Li D, Barreteau C, Brandbyge M. Proposal for All-Electrical Spin Manipulation and Detection for a Single Molecule on Boron-Substituted Graphene. PHYSICAL REVIEW LETTERS 2022; 129:027201. [PMID: 35867446 DOI: 10.1103/physrevlett.129.027201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/08/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
All-electrical writing and reading of spin states attract considerable attention for their promising applications in energy-efficient spintronics devices. Here we show, based on rigorous first-principles calculations, that the spin properties can be manipulated and detected in molecular spinterfaces, where an iron tetraphenyl porphyrin (FeTPP) molecule is deposited on boron-substituted graphene (BG). Notably, a reversible spin switching between the S=1 and S=3/2 states is achieved by a gate electrode. We can trace the origin to a strong hybridization between the Fe-d_{z^{2}} and B-p_{z} orbitals. Combining density functional theory with nonequilibrium Green's function formalism, we propose an experimentally feasible three-terminal setup to probe the spin state. Furthermore, we show how the in-plane quantum transport for the BG, which is non-spin polarized, can be modified by FeTPP, yielding a significant transport spin polarization near the Fermi energy (>10% for typical coverage). Our work paves the way to realize all-electrical spintronics devices using molecular spinterfaces.
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Affiliation(s)
- Fei Gao
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Dongzhe Li
- CEMES, Université de Toulouse, CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - Cyrille Barreteau
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette, France
| | - Mads Brandbyge
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
- Center for Nanostructured Graphene, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
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5
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Rubio-Verdú C, Zaldívar J, Žitko R, Pascual JI. Coupled Yu-Shiba-Rusinov States Induced by a Many-Body Molecular Spin on a Superconductor. PHYSICAL REVIEW LETTERS 2021; 126:017001. [PMID: 33480757 DOI: 10.1103/physrevlett.126.017001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
A magnetic impurity on a superconductor induces Yu-Shiba-Rusinov (YSR) bound states, detected by tunneling spectroscopy as long-lived quasiparticle excitations inside the superconducting gap. Coupled YSR states constitute basic elements to engineer artificial superconducting states, but their substrate-mediated interactions are generally weak. In this Letter, we report that intramolecular (Hund's-like) exchange interactions produce coupled YSR states across a molecular platform. We measured YSR spectra along a magnetic iron-porphyrin on Pb(111) and found evidence of two distinct interaction channels, which invert their particle-hole asymmetry across the molecule. Numerical calculations show that the identical YSR asymmetry pattern of the two channels is caused by two spin-hosting orbitals with opposite potential scattering and coupled strongly. Both channels can be similarly excited by tunneling electrons into each orbital, depicting a new scenario for entangled superconducting bound states using molecular platforms.
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Affiliation(s)
- Carmen Rubio-Verdú
- CIC nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
- Department of Physics, Columbia University, New York, New York 10027, United States
| | | | - Rok Žitko
- Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia
| | - Jose Ignacio Pascual
- CIC nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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6
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Zappe L, Schönfeld S, Hörner G, Zenere KA, Leong CF, Kepert CJ, D'Alessandro DM, Weber B, Neville SM. Spin crossover modulation in a coordination polymer with the redox-active bis-pyridyltetrathiafulvalene (py 2TTF) ligand. Chem Commun (Camb) 2020; 56:10469-10472. [PMID: 32766630 DOI: 10.1039/d0cc03788e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A one-dimensional FeII coordination polymer (CP) has been formed which includes the redox-active ligand bis-pyridyltetrathiafulvalene (py2TTF) and a Schiff base-like N2O2 ligand. This CP is both spin crossover (SCO) and redox-active in the solid-state, and chemical oxidation results in SCO modification.
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Affiliation(s)
- Lisa Zappe
- Department of Chemistry, University of Bayreuth, Universitätsstraße 30, 95448 Bayreuth, Germany.
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7
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Yin C, Peng Z, Liu D, Song H, Zhu H, Chen Q, Wu K. Selective Intramolecular Dehydrocyclization of Co-Porphyrin on Au(111). Molecules 2020; 25:molecules25173766. [PMID: 32824933 PMCID: PMC7503656 DOI: 10.3390/molecules25173766] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 12/02/2022] Open
Abstract
The on-surface C–H bond activation and coupling reaction is a powerful approach to constructing fine-tuned surface nanostructures. It is quite challenging to control its regioselectivity due to the inertness of the C–H bond involved. With scanning tunneling microscopy/spectroscopy and theoretical calculations, the C–H activation and sequential intramolecular dehydrocyclization of meso-tetra(p-methoxyphenyl)porphyrinatocobalt(II) was explored on Au(111), showing that the methoxy groups in the molecule could kinetically mediate the selectivity of the intramolecular reaction over its intermolecular coupling counterpart. The experimental results demonstrate that the introduced protecting group could help augment the selectivity of such on-surface reaction, which can be applied to the precise fabrication of functional surface nanostructures.
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Affiliation(s)
| | | | | | | | | | | | - Kai Wu
- Correspondence: (Q.C.); (K.W.)
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8
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Li J, Friedrich N, Merino N, de Oteyza DG, Peña D, Jacob D, Pascual JI. Electrically Addressing the Spin of a Magnetic Porphyrin through Covalently Connected Graphene Electrodes. NANO LETTERS 2019; 19:3288-3294. [PMID: 30964303 DOI: 10.1021/acs.nanolett.9b00883] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report on the fabrication and transport characterization of atomically precise single-molecule devices consisting of a magnetic porphyrin covalently wired by graphene nanoribbon electrodes. The tip of a scanning tunneling microscope was utilized to contact the end of a GNR-porphyrin-GNR hybrid system and create a molecular bridge between the tip and sample for transport measurements. Electrons tunneling through the suspended molecular heterostructure excited the spin multiplet of the magnetic porphyrin. The detachment of certain spin centers from the surface shifted their spin-carrying orbitals away from an on-surface mixed-valence configuration, recovering its original spin state. The existence of spin-polarized resonances in the free-standing systems and their electrical addressability is the fundamental step in the utilization of carbon-based materials as functional molecular spintronics systems.
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Affiliation(s)
- Jingcheng Li
- CIC nanoGUNE , Tolosa Hiribidea 76 , 20018 Donostia-San Sebastian , Spain
| | - Niklas Friedrich
- CIC nanoGUNE , Tolosa Hiribidea 76 , 20018 Donostia-San Sebastian , Spain
| | - Nestor Merino
- CIC nanoGUNE , Tolosa Hiribidea 76 , 20018 Donostia-San Sebastian , Spain
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastián , Spain
| | - Dimas G de Oteyza
- Donostia International Physics Center (DIPC) , 20018 Donostia-San Sebastián , Spain
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU) , 20018 Donostia-San Sebastián , Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao , Spain
| | - Diego Peña
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), and Departamento de Química Orgánica , Universidade de Santiago de Compostela , 15705 Santiago de Compostela , Spain
| | - David Jacob
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao , Spain
- Departamento de Física de Materiales , Universidad del País Vasco UPV/EHU , 20018 Donostia-San Sebastián , Spain
| | - Jose Ignacio Pascual
- CIC nanoGUNE , Tolosa Hiribidea 76 , 20018 Donostia-San Sebastian , Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao , Spain
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9
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Jasper-Tönnies T, Garcia-Lekue A, Frederiksen T, Ulrich S, Herges R, Berndt R. High-conductance contacts to functionalized molecular platforms physisorbed on Au(1 1 1). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:18LT01. [PMID: 30721893 DOI: 10.1088/1361-648x/ab0489] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The conductances of molecules physisorbed to Au(1 1 1) via an extended [Formula: see text] system are probed with the tip of a low-temperature scanning tunneling microscope to maximize the control of the junction geometry. Inert hydrogen, methyl, and reactive propynyl subunits were attached to the platform and stand upright. Because of their different reactivities, either non-bonding (hydrogen and methyl) or bonding (propynyl) tip-molecule contacts are formed. The conductances exhibit little scatter between different experimental runs on different molecules, display distinct evolutions with the tip-subunit distance, and reach contact values of 0.003-0.05 G 0. For equal tip-platform distances the contact conductance of the inert methyl is close to that of the reactive propynyl. Under further compression, the inert species, hydrogen and methyl, are found to be better conductors. This shows that the current flow is not directly correlated with the chemical interaction. Atomistic calculations for the methyl case reproduce the conductance evolution and reveal the role of the junction geometry, forces and orbital symmetries at the tip-molecule interface. The current flow is controlled by orbital symmetries at the electrode interfaces rather than by the energy alignment of the molecular orbitals and electrode states. Functionalized molecular platforms thus open new ways to control and engineer electron conduction through metal-molecule interfaces at the atomic level.
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Affiliation(s)
- Torben Jasper-Tönnies
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
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10
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Jia C, Wang X, Zhong W, Wang Z, Prezhdo OV, Luo Y, Jiang J. Catalytic Chemistry Predicted by a Charge Polarization Descriptor: Synergistic O 2 Activation and CO Oxidation by Au-Cu Bimetallic Clusters on TiO 2(101). ACS APPLIED MATERIALS & INTERFACES 2019; 11:9629-9640. [PMID: 30741519 DOI: 10.1021/acsami.9b00925] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The versatile properties of bimetallic nanoparticles greatly expand the range of catalyzed chemical reactions. We demonstrate that surface chemistry can be understood and predicted using a simple adsorbate-surface interaction descriptor that relates charge polarization to chemical reactivity. Our density functional theory studies of O2 activation and CO oxidation catalyzed by Au7-Cu1 bimetallic nanoparticles supported on the TiO2(101) surface demonstrate that the generated oxidized Cu atom (CuO x) can efficiently inhibit the aggregation of the active Cu sites. Moreover, because of the strong dipole-dipole interaction between the surface and the adsorbate on the oxidized Cu site, the adsorption of CO + O2/CO + O can be significantly enhanced, which can decrease the CO oxidation barriers and further improve catalytic performance. The product of the two electric dipole moments provides a parameter that allows us to predict the key catalytic properties for different adsorption sites and reaction pathways. The reported findings provide important insights into the mechanism of chemical reactivity of metallic clusters and generate a valuable principle for catalyst design.
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Affiliation(s)
| | - Xijun Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, School of Chemistry and Materials Science , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | | | | | - Oleg V Prezhdo
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Yi Luo
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, School of Chemistry and Materials Science , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Jun Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Mechanical Behavior and Design of Materials, School of Chemistry and Materials Science , University of Science and Technology of China , Hefei , Anhui 230026 , China
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11
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Stein A, Rolf D, Lotze C, Czekelius C, Franke KJ, Tegeder P. Electronic structure of an iron porphyrin derivative on Au(1 1 1). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:044002. [PMID: 30523801 DOI: 10.1088/1361-648x/aaf296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Surface-bound porphyrins are promising candidates for molecular switches, electronics and spintronics. Here, we studied the structural and the electronic properties of Fe-tetra-pyridil-porphyrin adsorbed on Au(1 1 1) in the monolayer regime. We combined scanning tunneling microscopy/spectroscopy, ultraviolet photoemission, and two-photon photoemission to determine the energy levels of the frontier molecular orbitals. We also resolved an excitonic state with a binding energy of 420 meV, which allowed us to compare the electronic transport gap with the optical gap.
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Affiliation(s)
- Arnulf Stein
- Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
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12
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Kügel J, Hsu PJ, Böhme M, Schneider K, Senkpiel J, Serrate D, Bode M, Lorente N. Jahn-Teller Splitting in Single Adsorbed Molecules Revealed by Isospin-Flip Excitations. PHYSICAL REVIEW LETTERS 2018; 121:226402. [PMID: 30547609 DOI: 10.1103/physrevlett.121.226402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 09/11/2018] [Indexed: 06/09/2023]
Abstract
Scanning tunneling spectroscopy measurements of Mn phthalocyanine (MnPc) molecules adsorbed on (sqrt[3]×sqrt[3]) surface alloys show single inelastic steps at exclusively positive or negative bias strongly depending on the tip position. This is in contrast to conventional molecular excitation thresholds, which are independent of the current direction and therefore always occur at both positive and negative bias. This polarity selectivity is found to coincide with the spatial distribution of occupied and empty orbitals. Because of the interaction with the substrate, charge transfer into the doubly degenerate d_{π} orbitals of MnPc takes place. The resulting Jahn-Teller effect lifts the degeneracy and leads to an isospin- or pseudospin-flip excitation, the inelastic analogue of an orbital Kondo resonance.
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Affiliation(s)
- Jens Kügel
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Pin-Jui Hsu
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Markus Böhme
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Kathrin Schneider
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jacob Senkpiel
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - David Serrate
- Instituto de Nanociencia de Aragón, Laboratorio de Microscopias Avanzadas, University of Zaragoza, E-50018 Zaragoza, Spain
- Departamento Física Materia Condensada, University of Zaragoza, E-50018 Zaragoza, Spain
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Wilhelm Conrad Röntgen-Center for Complex Material Systems (RCCM), Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Nicolás Lorente
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
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13
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Jacob D. Simulation of inelastic spin flip excitations and Kondo effect in STM spectroscopy of magnetic molecules on metal substrates. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:354003. [PMID: 30035748 DOI: 10.1088/1361-648x/aad523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Single-ion magnetic anisotropy in molecular magnets leads to spin flip excitations that can be measured by inelastic scanning tunneling microscope (STM) spectroscopy. Here I present a semi ab initio scheme to compute the spectral features associated with inelastic spin flip excitations and Kondo effect of single molecular magnets. To this end density functional theory calculations of the molecule on the substrate are combined with more sophisticated many-body techniques for solving the Anderson impurity problem of the spin-carrying orbitals of the magnetic molecule coupled to the rest of the system, containing a phenomenological magnetic anisotropy term. For calculating the STM spectra an exact expression for the [Formula: see text] in the ideal STM limit, when the coupling to the STM tip becomes negligibly small, is derived. In this limit the [Formula: see text] is simply related to the spectral function of the molecule-substrate system. For the case of an Fe porphyrin molecule on the Au(1 1 1) substrate, the calculated STM spectra are in good agreement with recently measured STM spectra, showing the typical step features at finite bias associated with spin flip excitation of a spin-1 quantum magnet. For the case of Kondo effect in Mn porphyrin on Au(1 1 1), the agreement with the experimental spectra is not as good due to the neglect of quantum interference in the tunneling.
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Affiliation(s)
- David Jacob
- Nano-Bio Spectroscopy Group, Dpto. de Física de Materiales, Universidad del País Vasco UPV/EHU, Avenida Tolosa 72, E-20018 San Sebastián, Spain. IKERBASQUE, Basque Foundation for Science, María Díaz de Haro 3, E-48013 Bilbao, Spain
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14
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Pope T, Du S, Gao HJ, Hofer WA. Electronic effects and fundamental physics studied in molecular interfaces. Chem Commun (Camb) 2018; 54:5508-5517. [PMID: 29726883 DOI: 10.1039/c8cc02191k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Scanning probe instruments in conjunction with a very low temperature environment have revolutionized the ability of building, functionalizing, and analysing two dimensional interfaces in the last twenty years. In addition, the availability of fast, reliable, and increasingly sophisticated methods to simulate the structure and dynamics of these interfaces allow us to capture even very small effects at the atomic and molecular level. In this review we shall focus largely on metal surfaces and organic molecular compounds and show that building systems from the bottom up and controlling the physical properties of such systems is no longer within the realm of the desirable, but has become day to day reality in our best laboratories.
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Affiliation(s)
- Thomas Pope
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
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