1
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Reale S, Hwang J, Oh J, Brune H, Heinrich AJ, Donati F, Bae Y. Electrically driven spin resonance of 4f electrons in a single atom on a surface. Nat Commun 2024; 15:5289. [PMID: 38902242 PMCID: PMC11190280 DOI: 10.1038/s41467-024-49447-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 06/05/2024] [Indexed: 06/22/2024] Open
Abstract
A pivotal challenge in quantum technologies lies in reconciling long coherence times with efficient manipulation of the quantum states of a system. Lanthanide atoms, with their well-localized 4f electrons, emerge as a promising solution to this dilemma if provided with a rational design for manipulation and detection. Here we construct tailored spin structures to perform electron spin resonance on a single lanthanide atom using a scanning tunneling microscope. A magnetically coupled structure made of an erbium and a titanium atom enables us to both drive the erbium's 4f electron spins and indirectly probe them through the titanium's 3d electrons. The erbium spin states exhibit an extended spin relaxation time and a higher driving efficiency compared to 3d atoms with spin ½ in similarly coupled structures. Our work provides a new approach to accessing highly protected spin states, enabling their coherent control in an all-electric fashion.
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Affiliation(s)
- Stefano Reale
- Center for Quantum Nanoscience (QNS), Institute for Basic Science (IBS), Seoul, Republic of Korea
- Ewha Womans University, Seoul, Republic of Korea
- Department of Energy, Politecnico di Milano, Milano, Italy
| | - Jiyoon Hwang
- Center for Quantum Nanoscience (QNS), Institute for Basic Science (IBS), Seoul, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul, Republic of Korea
| | - Jeongmin Oh
- Center for Quantum Nanoscience (QNS), Institute for Basic Science (IBS), Seoul, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul, Republic of Korea
| | - Harald Brune
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Andreas J Heinrich
- Center for Quantum Nanoscience (QNS), Institute for Basic Science (IBS), Seoul, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul, Republic of Korea
| | - Fabio Donati
- Center for Quantum Nanoscience (QNS), Institute for Basic Science (IBS), Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, Seoul, Republic of Korea.
| | - Yujeong Bae
- Center for Quantum Nanoscience (QNS), Institute for Basic Science (IBS), Seoul, Republic of Korea.
- Department of Physics, Ewha Womans University, Seoul, Republic of Korea.
- Empa, Swiss Federal Laboratories for Materials Science and Technology, nanotech@surfaces Laboratory, Dübendorf, Switzerland.
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2
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Wang F, Shen W, Shui Y, Chen J, Wang H, Wang R, Qin Y, Wang X, Wan J, Zhang M, Lu X, Yang T, Song F. Electrically controlled nonvolatile switching of single-atom magnetism in a Dy@C 84 single-molecule transistor. Nat Commun 2024; 15:2450. [PMID: 38503743 PMCID: PMC10951203 DOI: 10.1038/s41467-024-46854-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/12/2024] [Indexed: 03/21/2024] Open
Abstract
Single-atom magnetism switching is a key technique towards the ultimate data storage density of computer hard disks and has been conceptually realized by leveraging the spin bistability of a magnetic atom under a scanning tunnelling microscope. However, it has rarely been applied to solid-state transistors, an advancement that would be highly desirable for enabling various applications. Here, we demonstrate realization of the electrically controlled Zeeman effect in Dy@C84 single-molecule transistors, thus revealing a transition in the magnetic moment from 3.8μ B to 5.1μ B for the ground-state GN at an electric field strength of 3 - 10 MV/cm. The consequent magnetoresistance significantly increases from 600% to 1100% at the resonant tunneling point. Density functional theory calculations further corroborate our realization of nonvolatile switching of single-atom magnetism, and the switching stability emanates from an energy barrier of 92 meV for atomic relaxation. These results highlight the potential of using endohedral metallofullerenes for high-temperature, high-stability, high-speed, and compact single-atom magnetic data storage.
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Affiliation(s)
- Feng Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
- Institute of Atom Manufacturing, Nanjing University, Suzhou, 215163, China
| | - Wangqiang Shen
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
- School of Materials Science and Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yuan Shui
- MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jun Chen
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
- Institute of Atom Manufacturing, Nanjing University, Suzhou, 215163, China
| | - Huaiqiang Wang
- Center for Quantum Transport and Thermal Energy Science, School of Physics and Technology, Nanjing Normal University, Nanjing, 210023, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Yuyuan Qin
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Xuefeng Wang
- State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, China
| | - Jianguo Wan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China
| | - Minhao Zhang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China.
- Institute of Atom Manufacturing, Nanjing University, Suzhou, 215163, China.
| | - Xing Lu
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Tao Yang
- MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, 210093, China.
- Institute of Atom Manufacturing, Nanjing University, Suzhou, 215163, China.
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3
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Vieru V, Gómez-Coca S, Ruiz E, Chibotaru LF. Increasing the Magnetic Blocking Temperature of Single-Molecule Magnets. Angew Chem Int Ed Engl 2024; 63:e202303146. [PMID: 37539652 DOI: 10.1002/anie.202303146] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/18/2023] [Accepted: 08/02/2023] [Indexed: 08/05/2023]
Abstract
The synthesis of single-molecule magnets (SMMs), magnetic complexes capable of retaining magnetization blocking for a long time at elevated temperatures, has been a major concern for magnetochemists over the last three decades. In this review, we describe basic SMMs and the different approaches that allow high magnetization-blocking temperatures to be reached. We focus on the basic factors affecting magnetization blocking, magnetic axiality and the height of the blocking barrier, which can be used to group different families of complexes in terms of their SMM efficiency. Finally, we discuss several practical routes for the design of mono- and polynuclear complexes that could be applied in memory devices.
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Affiliation(s)
- Veacheslav Vieru
- Maastricht Science Programme, Faculty of Science and Engineering, Maastricht University, 6229 EN, Maastricht, The Netherlands
| | - Silvia Gómez-Coca
- Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, 08028, Barcelona, Spain
- Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Eliseo Ruiz
- Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, 08028, Barcelona, Spain
- Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Liviu F Chibotaru
- Theory of Nanomaterials Group, Katholieke Universiteit Leuven, 3001, Leuven, Belgium
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4
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Zhang X, Reina-Gálvez J, Wolf C, Wang Y, Aubin H, Heinrich AJ, Choi T. Influence of the Magnetic Tip on Heterodimers in Electron Spin Resonance Combined with Scanning Tunneling Microscopy. ACS NANO 2023; 17:16935-16942. [PMID: 37643247 DOI: 10.1021/acsnano.3c04024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Investigating the quantum properties of individual spins adsorbed on surfaces by electron spin resonance combined with scanning tunneling microscopy (ESR-STM) has shown great potential for the development of quantum information technology on the atomic scale. A magnetic tip exhibiting high spin polarization is critical for performing an ESR-STM experiment. While the tip has been conventionally treated as providing a static magnetic field in ESR-STM, it was found that the tip can exhibit bistability, influencing ESR spectra. Ideally, the ESR splitting caused by the magnetic interaction between two spins on a surface should be independent of the tip. However, we found that the measured ESR splitting of a metal atom-molecule heterodimer can be tip-dependent. Detailed theoretical analysis reveals that this tip-dependent ESR splitting is caused by a different interaction energy between the tip and each spin of the heterodimer. Our work provides a comprehensive reference for characterizing tip features in ESR-STM experiments and highlights the importance of employing a proper physical model when describing the ESR tip, in particular, for heterospin systems.
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Affiliation(s)
- Xue Zhang
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
- Spin-X Institute, School of Microelectronics, South China University of Technology, Guangzhou 511442, People's Republic of China
| | - Jose Reina-Gálvez
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Christoph Wolf
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Yu Wang
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hervé Aubin
- Universités Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120 Palaiseau, France
| | - Andreas J Heinrich
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Taeyoung Choi
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
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5
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Phark S, Bui HT, Ferrón A, Fernández‐Rossier J, Reina‐Gálvez J, Wolf C, Wang Y, Yang K, Heinrich AJ, Lutz CP. Electric-Field-Driven Spin Resonance by On-Surface Exchange Coupling to a Single-Atom Magnet. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302033. [PMID: 37466177 PMCID: PMC10520627 DOI: 10.1002/advs.202302033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/11/2023] [Indexed: 07/20/2023]
Abstract
Coherent control of individual atomic and molecular spins on surfaces has recently been demonstrated by using electron spin resonance (ESR) in a scanning tunneling microscope (STM). Here, a combined experimental and modeling study of the ESR of a single hydrogenated Ti atom that is exchange-coupled to a Fe adatom positioned 0.6-0.8 nm away by means of atom manipulation is presented. Continuous wave and pulsed ESR of the Ti spin show a Rabi rate with two contributions, one from the tip and the other from the Fe, whose spin interactions with Ti are modulated by the radio-frequency electric field. The Fe contribution is comparable to the tip, as revealed by its dominance when the tip is retracted, and tunable using a vector magnetic field. The new ESR scheme allows on-surface individual spins to be addressed and coherently controlled without the need for magnetic interaction with a tip. This study establishes a feasible implementation of spin-based multi-qubit systems on surfaces.
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Affiliation(s)
- Soo‐hyon Phark
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)Seoul03760Republic of Korea
- Department of PhysicsEwha Womans UniversitySeoul03760Republic of Korea
- IBM Research DivisionAlmaden Research CenterSan JoseCA95120USA
| | - Hong Thi Bui
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)Seoul03760Republic of Korea
- Department of PhysicsEwha Womans UniversitySeoul03760Republic of Korea
| | - Alejandro Ferrón
- Instituto de Modelado e Innovación Tecnológica (CONICET‐UNNE) and Facultad de Ciencias ExactasNaturales y AgrimensuraUniversidad Nacional del NordesteAvenida Libertad 5400CorrientesW3404AASArgentina
| | | | - Jose Reina‐Gálvez
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)Seoul03760Republic of Korea
- Department of PhysicsEwha Womans UniversitySeoul03760Republic of Korea
| | - Christoph Wolf
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)Seoul03760Republic of Korea
- Department of PhysicsEwha Womans UniversitySeoul03760Republic of Korea
| | - Yu Wang
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)Seoul03760Republic of Korea
- Department of PhysicsEwha Womans UniversitySeoul03760Republic of Korea
| | - Kai Yang
- IBM Research DivisionAlmaden Research CenterSan JoseCA95120USA
- Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing100864China
| | - Andreas J. Heinrich
- Center for Quantum NanoscienceInstitute for Basic Science (IBS)Seoul03760Republic of Korea
- Department of PhysicsEwha Womans UniversitySeoul03760Republic of Korea
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6
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Curcella A, Sblendorio D, Rusponi S, Pivetta M, Patthey F, Brune H. Valence Orbitals Driving the Spin Dynamics in a Rare-Earth Single-Atom Magnet. PHYSICAL REVIEW LETTERS 2023; 130:106702. [PMID: 36962040 DOI: 10.1103/physrevlett.130.106702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/17/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
We combine spin-polarized scanning tunneling microscopy with quantum master equation analysis to investigate the spin dynamics of the single atom magnet Dy on graphene/Ir(111). By performing reading and writing experiments, we show that the strongly spin polarized 5d6s valence shells, as well as their intra-atomic exchange coupling to the 4f shell, determine the pathways for magnetization relaxation and thus the spin dynamics. The good quantum number that determines which states are stable and which mechanisms for reversal exist in a given crystal field is the atomic total angular momentum J_{z}^{tot} and not the commonly considered J_{z}^{4f} of the 4f shell only.
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Affiliation(s)
- A Curcella
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - D Sblendorio
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - S Rusponi
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - M Pivetta
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - F Patthey
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - H Brune
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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7
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Zhou Y, Jiang Y, Ji Y, Lang R, Fang Y, Wu C. The Opportunities and Challenges in Single‐Atom Catalysis. ChemCatChem 2023. [DOI: 10.1002/cctc.202201176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- Yang Zhou
- School of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China
| | - Yan Jiang
- School of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China
| | - Yuxia Ji
- School of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China
| | - Rui Lang
- School of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery Guangzhou 510006 P. R. China
- Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory (Rongjiang Laboratory) Jieyang 515200 P. R. China
| | - Yanxiong Fang
- School of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery Guangzhou 510006 P. R. China
- Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory (Rongjiang Laboratory) Jieyang 515200 P. R. China
| | - Chuan‐De Wu
- School of Chemical Engineering and Light Industry Guangdong University of Technology Guangzhou 510006 P. R. China
- State Key Laboratory of Silicon Materials Department of Chemistry Zhejiang University Hangzhou 310027 P. R. China
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8
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Kawaguchi R, Hashimoto K, Kakudate T, Katoh K, Yamashita M, Komeda T. Spatially Resolving Electron Spin Resonance of π-Radical in Single-molecule Magnet. NANO LETTERS 2023; 23:213-219. [PMID: 36585948 PMCID: PMC9838557 DOI: 10.1021/acs.nanolett.2c04049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/27/2022] [Indexed: 06/17/2023]
Abstract
The spintronic properties of magnetic molecules have attracted significant scientific attention. Special emphasis has been placed on the qubit for quantum information processing. The single-molecule magnet bis(phthalocyaninato (Pc)) Tb(III) (TbPc2) is one of the best examined cases in which the delocalized π-radical electron spin of the Pc ligand plays the key role in reading and intermediating the localized Tb spin qubits. We utilized the electron spin resonance (ESR) technique implemented on a scanning tunneling microscope (STM) and use it to measure local the ESR of a single TbPc2 molecule decoupled from the Cu(100) substrate by a two-monolayer NaCl film to identify the π-radical spin. We detected the ESR signal at the ligand positions under the resonance condition expected for an S = 1/2 spin. The results reveal that the π-radical electron is delocalized within the ligands and exhibits intramolecular coupling susceptible to the chemical environment.
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Affiliation(s)
- Ryo Kawaguchi
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, Sendai980-0877, Japan
| | - Katsushi Hashimoto
- Department
of Physics, Graduate School of Sciences, Tohoku University, Sendai980-8578, Japan
- Center
for Science and Innovation in Spintronics (Core Research Cluster), Tohoku University, Sendai980-8577, Japan
| | - Toshiyuki Kakudate
- Department
of Industrial Systems Engineering, National
Institute of Technology (KOSEN), Hachinohe
College, 16-1 Uwanotai, Tamonoki, Hachinohe039-1192, Japan
| | - Keiichi Katoh
- Department
of Chemistry, Graduate School of Science, Josai University, Sakado, Saitama350-0295, Japan
| | - Masahiro Yamashita
- Department
of Chemistry, Graduate School of Science, Tohoku University, Sendai980-8578, Japan
- School
of Materials Science and Engineering, Nankai
University, Tianjin300350, People’s Republic of China
| | - Tadahiro Komeda
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, Sendai980-0877, Japan
- Center
for Science and Innovation in Spintronics (Core Research Cluster), Tohoku University, Sendai980-8577, Japan
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9
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Bellini V, Rusponi S, Kolorenč J, Mahatha SK, Valbuena MA, Persichetti L, Pivetta M, Sorokin BV, Merk D, Reynaud S, Sblendorio D, Stepanow S, Nistor C, Gargiani P, Betto D, Mugarza A, Gambardella P, Brune H, Carbone C, Barla A. Slow Magnetic Relaxation of Dy Adatoms with In-Plane Magnetic Anisotropy on a Two-Dimensional Electron Gas. ACS NANO 2022; 16:11182-11193. [PMID: 35770912 PMCID: PMC9330770 DOI: 10.1021/acsnano.2c04048] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report on the magnetic properties of Dy atoms adsorbed on the (001) surface of SrTiO3. X-ray magnetic circular dichroism reveals slow relaxation of the Dy magnetization on a time scale of about 800 s at 2.5 K, unusually associated with an easy-plane magnetic anisotropy. We attribute these properties to Dy atoms occupying hollow adsorption sites on the TiO2-terminated surface. Conversely, Ho atoms adsorbed on the same surface show paramagnetic behavior down to 2.5 K. With the help of atomic multiplet simulations and first-principles calculations, we establish that Dy populates also the top-O and bridge sites on the coexisting SrO-terminated surface. A simple magnetization relaxation model predicts these two sites to have an even longer magnetization lifetime than the hollow site. Moreover, the adsorption of Dy on the insulating SrTiO3 crystal leads, regardless of the surface termination, to the formation of a spin-polarized two-dimensional electron gas of Ti 3dxy character, together with an antiferromagnetic Dy-Ti coupling. Our findings support the feasibility of tuning the magnetic properties of the rare-earth atoms by acting on the substrate electronic gas with electric fields.
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Affiliation(s)
- Valerio Bellini
- S3-Istituto
di Nanoscienze-CNR, Via
Campi 213/A, I-41125 Modena, Italy
| | - Stefano Rusponi
- Institute
of Physics, Ecole Polytechnique Fédérale de Lausanne
(EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - Jindřich Kolorenč
- Institute
of Physics (FZU), Czech Academy of Sciences, Na Slovance 2, CZ-182
21 Prague, Czech Republic
| | - Sanjoy K. Mahatha
- Istituto
di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche
(CNR), I-34149 Trieste, Italy
- School
of
Physics and Materials Science, Thapar Institute
of Engineering and Technology, Patiala 147004, India
| | - Miguel Angel Valbuena
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST,
Campus UAB, Bellaterra, E-08193 Barcelona, Spain
- Instituto
Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanoscience), E-28049 Madrid, Spain
| | - Luca Persichetti
- Department
of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
- Dipartimento
di Fisica, Università di Roma “Tor
Vergata”, I-00133 Roma, Italy
| | - Marina Pivetta
- Institute
of Physics, Ecole Polytechnique Fédérale de Lausanne
(EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - Boris V. Sorokin
- Institute
of Physics, Ecole Polytechnique Fédérale de Lausanne
(EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - Darius Merk
- Institute
of Physics, Ecole Polytechnique Fédérale de Lausanne
(EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - Sébastien Reynaud
- Institute
of Physics, Ecole Polytechnique Fédérale de Lausanne
(EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - Dante Sblendorio
- Institute
of Physics, Ecole Polytechnique Fédérale de Lausanne
(EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | | | - Corneliu Nistor
- Department
of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | | | - Davide Betto
- European
Synchrotron Radiation Facility, F-38043 Grenoble Cedex, France
| | - Aitor Mugarza
- Catalan
Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST,
Campus UAB, Bellaterra, E-08193 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avançats (ICREA), Barcelona E-08010, Spain
| | | | - Harald Brune
- Institute
of Physics, Ecole Polytechnique Fédérale de Lausanne
(EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - Carlo Carbone
- Istituto
di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche
(CNR), I-34149 Trieste, Italy
| | - Alessandro Barla
- Istituto
di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche
(CNR), I-34149 Trieste, Italy
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10
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Herman A, Kraus S, Tsukamoto S, Spieker L, Caciuc V, Lojewski T, Günzing D, Dreiser J, Delley B, Ollefs K, Michely T, Atodiresei N, Wende H. Tailoring magnetic anisotropy by graphene-induced selective skyhook effect on 4f-metals. NANOSCALE 2022; 14:7682-7691. [PMID: 35546135 DOI: 10.1039/d2nr01458k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
From macroscopic heavy-duty permanent magnets to nanodevices, the precise control of the magnetic properties in rare-earth metals is crucial for many applications used in our daily life. Therefore, a detailed understanding and manipulation of the 4f-metals' magnetic properties are key to further boosting the functionalization and efficiency of future applications. We present a proof-of-concept approach consisting of a dysprosium-iridium surface alloy in which graphene adsorption allows us to tailor its magnetic properties. By adsorbing graphene onto a long-range ordered two-dimensional dysprosium-iridium surface alloy, the magnetic 4f-metal atoms are selectively lifted from the surface alloy. This selective skyhook effect introduces a giant magnetic anisotropy in dysprosium atoms as a result of manipulating its geometrical structure within the surface alloy. Introducing and proving this concept by our combined theoretical and experimental approach provides an easy and unambiguous understanding of its underlying mechanism. Our study sets the ground for an alternative path on how to modify the crystal field around 4f-atoms and therefore their magnetic anisotropies.
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Affiliation(s)
- Alexander Herman
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47058 Duisburg, Germany.
| | - Stefan Kraus
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany
| | - Shigeru Tsukamoto
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Lea Spieker
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47058 Duisburg, Germany.
| | - Vasile Caciuc
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Tobias Lojewski
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47058 Duisburg, Germany.
| | - Damian Günzing
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47058 Duisburg, Germany.
| | - Jan Dreiser
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Bernard Delley
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Katharina Ollefs
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47058 Duisburg, Germany.
| | - Thomas Michely
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany
| | - Nicolae Atodiresei
- Peter Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Heiko Wende
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47058 Duisburg, Germany.
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11
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Kovarik S, Robles R, Schlitz R, Seifert TS, Lorente N, Gambardella P, Stepanow S. Electron Paramagnetic Resonance of Alkali Metal Atoms and Dimers on Ultrathin MgO. NANO LETTERS 2022; 22:4176-4181. [PMID: 35512394 DOI: 10.1021/acs.nanolett.2c00980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Electron paramagnetic resonance (EPR) can provide unique insight into the chemical structure and magnetic properties of dopants in oxide and semiconducting materials that are of interest for applications in electronics, catalysis, and quantum sensing. Here, we demonstrate that EPR in combination with scanning tunneling microscopy (STM) allows for probing the bonding and charge state of alkali metal atoms on an ultrathin magnesium oxide layer on a Ag substrate. We observe a magnetic moment of 1 μB for Li2, LiNa, and Na2 dimers corresponding to spin radicals with a charge state of +1e. Single alkali atoms have the same charge state and no magnetic moment. The ionization of the adsorbates is attributed to charge transfer through the oxide to the metal substrate. Our work highlights the potential of EPR-STM to provide insight into dopant atoms that are relevant for the control of the electrical properties of surfaces and nanodevices.
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Affiliation(s)
- Stepan Kovarik
- Department of Materials, ETH Zurich, Hönggerbergring 64, Zürich CH-8093, Switzerland
| | - Roberto Robles
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, San Sebastián 20018, Spain
| | - Richard Schlitz
- Department of Materials, ETH Zurich, Hönggerbergring 64, Zürich CH-8093, Switzerland
| | - Tom Sebastian Seifert
- Department of Materials, ETH Zurich, Hönggerbergring 64, Zürich CH-8093, Switzerland
- Department of Physics, Freie Universität Berlin, Berlin 14195, Germany
| | - Nicolas Lorente
- Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, San Sebastián 20018, Spain
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, San Sebastián 20018, Spain
| | - Pietro Gambardella
- Department of Materials, ETH Zurich, Hönggerbergring 64, Zürich CH-8093, Switzerland
| | - Sebastian Stepanow
- Department of Materials, ETH Zurich, Hönggerbergring 64, Zürich CH-8093, Switzerland
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12
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Navrátil J, Otyepka M, Błoński P. OsPd bimetallic dimer pushes the limit of magnetic anisotropy in atom-sized magnets for data storage. NANOTECHNOLOGY 2022; 33:215001. [PMID: 35147526 DOI: 10.1088/1361-6528/ac5447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
The growing gap between the volume of digital data being created and the extent of available storage capacities stimulates intensive research into surface-supported, well-ordered array of atom-sized magnets that represents the ultimate limit of magnetic data storage. Anchoring transition-metal heterodimers in vacancy defects in the graphene lattice has been identified as a vivid strategy to achieve large magnetic anisotropy energy (MAE) up to 80 meV with an easy axis aligned along the dimer bond. In this paper we have made a significant leap forward finding out MAE of 119 meV for an OsPt dimer and 170 meV for an OsPd dimer bound to a single nitrogen-decorated vacancy defect. The system with the highest MAE and with the theoretical storage density of ∼490 Tb·inch-2pushes the current limit of theoretical blocking temperature in graphene-supported transition-metal dimers from ∼20 to ∼44 K assuming the relaxation time of 10 years. The mechanism of the enhanced MAE is discussed.
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Affiliation(s)
- Jan Navrátil
- Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, tř. 17 listopadu 12, 779 00 Olomouc, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, 779 00 Olomouc, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, 779 00 Olomouc, Czech Republic
| | - Piotr Błoński
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, 779 00 Olomouc, Czech Republic
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13
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Aras M, Güler-Kılıç S, Kılıç Ç. Enhancement of the magnetic anisotropy in single semiconductor nanowires via surface doping and adatom deposition. NANOTECHNOLOGY 2022; 33:205202. [PMID: 35105830 DOI: 10.1088/1361-6528/ac50f0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
The magnetic anisotropy of single semiconductor (ZnO and GaN) nanowires incorporating both a transition metal (Co and Mn, respectively) as a substitutional surface dopant and a heavy metal (Au, Bi, or Pt) adatom is studied by performing density-functional supercell calculations with the HubbardUcorrection. It is found that a substantial enhancement in the magnetic anisotropy energy is obtained through the deposition of Bi; the deposition of Au and Pt leads to significant variation in other magnetic properties, but not in the magnetic anisotropy energy. An analysis within a band description shows that the coexistence of Bi adatom and a surface dopant with large spin moment activates a mechanism involving reorientation and readjustment of the spin moments of electrons in occupied bands in response to the change of magnetization direction, which promotes giant magnetic anisotropy. Our results for adsorption energetics indicate that the accommodation of Bi in the neighborhood of the surface dopant is more likely in GaN nanowires, because the Bi adatom does (not) tend to be closer to the Mn (Co) dopant on the surface of GaN (ZnO) nanowire. The stability of GaN nanowire with giant magnetic anisotropy owing to the incorporation of both Mn and Bi is demonstrated by performingab initiomolecular dynamics simulations at temperatures considerably higher than room temperature. These results suggest that adatom deposition and surface doping can be used complementarily to develop single nanowire-based spintronic devices.
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Affiliation(s)
- Mehmet Aras
- Department of Physics, Gebze Technical University, Gebze, Kocaeli 41400, Turkey
| | - Sümeyra Güler-Kılıç
- Department of Physics, Gebze Technical University, Gebze, Kocaeli 41400, Turkey
| | - Çetin Kılıç
- Department of Physics, Gebze Technical University, Gebze, Kocaeli 41400, Turkey
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14
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Vlaic S, Mousadakos D, Ouazi S, Rusponi S, Brune H. Increasing Magnetic Anisotropy in Bimetallic Nanoislands Grown on fcc(111) Metal Surfaces. NANOMATERIALS 2022; 12:nano12030518. [PMID: 35159863 PMCID: PMC8840744 DOI: 10.3390/nano12030518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 11/23/2022]
Abstract
The magnetic properties and the atomic scale morphology of bimetallic two-dimensional nanoislands, epitaxially grown on fcc(111) metal surfaces, have been studied by means of Magneto-Optical Kerr Effect and Scanning Tunneling Microscopy. We investigate the effect on blocking temperature of one-dimensional interlines appearing in core-shell structures, of two-dimensional interfaces created by capping, and of random alloying. The islands are grown on Pt(111) and contain a Co-core, surrounded by Ag, Rh, and Pd shells, or capped by Pd. The largest effect is obtained by Pd capping, increasing the blocking temperature by a factor of three compared to pure Co islands. In addition, for Co-core Fe-shell and Co-core FexCo1−x-shell islands, self-assembled into well ordered superlattices on Au(11,12,12) vicinal surfaces, we find a strong enhancement of the blocking temperature compared to pure Co islands of the same size. These ultra-high-density (15 Tdots/in2) superlattices of CoFe nanodots, only 500 atoms in size, have blocking temperature exceeding 100 K. Our findings open new possibilities to tailor the magnetic properties of nanoislands.
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Affiliation(s)
- Sergio Vlaic
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (S.V.); (D.M.); (S.O.); (S.R.)
- Laboratoire de Physique et d’Étude des Matériaux (LPEM), ESPCI Paris-PSL Universtity, CNRS UMR8213, Sorbonne Université, 75005 Paris, France
| | - Dimitris Mousadakos
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (S.V.); (D.M.); (S.O.); (S.R.)
| | - Safia Ouazi
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (S.V.); (D.M.); (S.O.); (S.R.)
| | - Stefano Rusponi
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (S.V.); (D.M.); (S.O.); (S.R.)
| | - Harald Brune
- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland; (S.V.); (D.M.); (S.O.); (S.R.)
- Correspondence:
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15
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Chen Y, Bae Y, Heinrich AJ. Harnessing the Quantum Behavior of Spins on Surfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2107534. [PMID: 34994026 DOI: 10.1002/adma.202107534] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/28/2021] [Indexed: 06/14/2023]
Abstract
The desire to control and measure individual quantum systems such as atoms and ions in a vacuum has led to significant scientific and engineering developments in the past decades that form the basis of today's quantum information science. Single atoms and molecules on surfaces, on the other hand, are heavily investigated by physicists, chemists, and material scientists in search of novel electronic and magnetic functionalities. These two paths crossed in 2015 when it was first clearly demonstrated that individual spins on a surface can be coherently controlled and read out in an all-electrical fashion. The enabling technique is a combination of scanning tunneling microscopy (STM) and electron spin resonance, which offers unprecedented coherent controllability at the Angstrom length scale. This review aims to illustrate the essential ingredients that allow the quantum operations of single spins on surfaces. Three domains of applications of surface spins, namely quantum sensing, quantum control, and quantum simulation, are discussed with physical principles explained and examples presented. Enabled by the atomically-precise fabrication capability of STM, single spins on surfaces might one day lead to the realization of quantum nanodevices and artificial quantum materials at the atomic scale.
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Affiliation(s)
- Yi Chen
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul, 03760, Korea
- Department of Physics, Ewha Womans University, Seoul, 03760, Korea
| | - Yujeong Bae
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul, 03760, Korea
- Department of Physics, Ewha Womans University, Seoul, 03760, Korea
| | - Andreas J Heinrich
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul, 03760, Korea
- Department of Physics, Ewha Womans University, Seoul, 03760, Korea
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16
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Singha A, Sostina D, Wolf C, Ahmed SL, Krylov D, Colazzo L, Gargiani P, Agrestini S, Noh WS, Park JH, Pivetta M, Rusponi S, Brune H, Heinrich AJ, Barla A, Donati F. Mapping Orbital-Resolved Magnetism in Single Lanthanide Atoms. ACS NANO 2021; 15:16162-16171. [PMID: 34546038 DOI: 10.1021/acsnano.1c05026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Single lanthanide atoms and molecules are promising candidates for atomic data storage and quantum logic due to the long lifetime of their magnetic quantum states. Accessing and controlling these states through electrical transport requires precise knowledge of their electronic configuration at the level of individual atomic orbitals, especially of the outer shells involved in transport. However, no experimental techniques have so far shown the required sensitivity to probe single atoms with orbital selectivity. Here we resolve the magnetism of individual orbitals in Gd and Ho single atoms on MgO/Ag(100) by combining X-ray magnetic circular dichroism with multiplet calculations and density functional theory. In contrast to the usual assumption of bulk-like occupation of the different electronic shells, we establish a charge transfer mechanism leading to an unconventional singly ionized configuration. Our work identifies the role of the valence electrons in determining the quantum level structure and spin-dependent transport properties of lanthanide-based nanomagnets.
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Affiliation(s)
- Aparajita Singha
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
- Max Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Daria Sostina
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Christoph Wolf
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Safa L Ahmed
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Denis Krylov
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Luciano Colazzo
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Pierluigi Gargiani
- ALBA Synchrotron Light Source, Cerdanyola del Vallès, 08290 Catalonia, Spain
| | - Stefano Agrestini
- ALBA Synchrotron Light Source, Cerdanyola del Vallès, 08290 Catalonia, Spain
| | - Woo-Suk Noh
- MPPC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang 37673, Republic of Korea
| | - Jae-Hoon Park
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Marina Pivetta
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Stefano Rusponi
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Harald Brune
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Andreas J Heinrich
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Alessandro Barla
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), I-34149 Trieste, Italy
| | - Fabio Donati
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
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17
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Donati F, Pivetta M, Wolf C, Singha A, Wäckerlin C, Baltic R, Fernandes E, de Groot JG, Ahmed SL, Persichetti L, Nistor C, Dreiser J, Barla A, Gambardella P, Brune H, Rusponi S. Correlation between Electronic Configuration and Magnetic Stability in Dysprosium Single Atom Magnets. NANO LETTERS 2021; 21:8266-8273. [PMID: 34569802 DOI: 10.1021/acs.nanolett.1c02744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Single atom magnets offer the possibility of magnetic information storage in the most fundamental unit of matter. Identifying the parameters that control the stability of their magnetic states is crucial to design novel quantum magnets with tailored properties. Here, we use X-ray absorption spectroscopy to show that the electronic configuration of dysprosium atoms on MgO(100) thin films can be tuned by the proximity of the metal Ag(100) substrate onto which the MgO films are grown. Increasing the MgO thickness from 2.5 to 9 monolayers induces a change in the dysprosium electronic configuration from 4f9 to 4f10. Hysteresis loops indicate long magnetic lifetimes for both configurations, however, with a different field-dependent magnetic stability. Combining these measurements with scanning tunneling microscopy, density functional theory, and multiplet calculations unveils the role of the adsorption site and charge transfer to the substrate in determining the stability of quantum states in dysprosium single atom magnets.
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Affiliation(s)
- Fabio Donati
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Marina Pivetta
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Christoph Wolf
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
| | - Aparajita Singha
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Ewha Womans University, Seoul 03760, Republic of Korea
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - Christian Wäckerlin
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
- Surface Science and Coating Technologies, Empa - Swiss Federal Laboratories for Materials Research and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland
| | - Romana Baltic
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Edgar Fernandes
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Jean-Guillaume de Groot
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Safa Lamia Ahmed
- Center for Quantum Nanoscience, Institute for Basic Science (IBS), Seoul 03760, Republic of Korea
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Luca Persichetti
- Department of Materials, ETH Zurich, Hönggerbergring 64, CH-8093 Zurich, Switzerland
- Department of Sciences, Roma Tre University, I-00146, Roma, Italy
| | - Corneliu Nistor
- Department of Materials, ETH Zurich, Hönggerbergring 64, CH-8093 Zurich, Switzerland
| | - Jan Dreiser
- Swiss Light Source (SLS), Paul Scherrer Institute (PSI), CH-5232 Villigen PSI, Switzerland
| | - Alessandro Barla
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), I-34149 Trieste, Italy
| | - Pietro Gambardella
- Department of Materials, ETH Zurich, Hönggerbergring 64, CH-8093 Zurich, Switzerland
| | - Harald Brune
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
| | - Stefano Rusponi
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne, Switzerland
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