1
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Sen S, Mitchell AK. Many-Body Quantum Interference Route to the Two-Channel Kondo Effect: Inverse Design for Molecular Junctions and Quantum Dot Devices. PHYSICAL REVIEW LETTERS 2024; 133:076501. [PMID: 39213568 DOI: 10.1103/physrevlett.133.076501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 05/22/2024] [Accepted: 07/15/2024] [Indexed: 09/04/2024]
Abstract
Molecular junctions-whether actual single molecules in nanowire break junctions or artificial molecules realized in coupled quantum dot devices-offer unique functionality due to their orbital complexity, strong electron interactions, gate control, and many-body effects from hybridization with the external electronic circuit. Inverse design involves finding candidate structures that perform a desired function optimally. Here we develop an inverse design strategy for generalized quantum impurity models describing molecular junctions, and as an example, use it to demonstrate that many-body quantum interference can be leveraged to realize the two-channel Kondo critical point in simple 4- or 5-site molecular moieties. We show that remarkably high Kondo temperatures can be achieved, meaning that entropy and transport signatures should be experimentally accessible.
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2
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Xu X, Gao C, Emusani R, Jia C, Xiang D. Toward Practical Single-Molecule/Atom Switches. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400877. [PMID: 38810145 PMCID: PMC11304318 DOI: 10.1002/advs.202400877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/29/2024] [Indexed: 05/31/2024]
Abstract
Electronic switches have been considered to be one of the most important components of contemporary electronic circuits for processing and storing digital information. Fabricating functional devices with building blocks of atomic/molecular switches can greatly promote the minimization of the devices and meet the requirement of high integration. This review highlights key developments in the fabrication and application of molecular switching devices. This overview offers valuable insights into the switching mechanisms under various stimuli, emphasizing structural and energy state changes in the core molecules. Beyond the molecular switches, typical individual metal atomic switches are further introduced. A critical discussion of the main challenges for realizing and developing practical molecular/atomic switches is provided. These analyses and summaries will contribute to a comprehensive understanding of the switch mechanisms, providing guidance for the rational design of functional nanoswitch devices toward practical applications.
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Affiliation(s)
- Xiaona Xu
- Institute of Modern Optics and Center of Single Molecule SciencesNankai UniversityTianjin Key Laboratory of Micro‐scale Optical Information Science and TechnologyTianjin300350China
| | - Chunyan Gao
- Institute of Modern Optics and Center of Single Molecule SciencesNankai UniversityTianjin Key Laboratory of Micro‐scale Optical Information Science and TechnologyTianjin300350China
| | - Ramya Emusani
- Institute of Modern Optics and Center of Single Molecule SciencesNankai UniversityTianjin Key Laboratory of Micro‐scale Optical Information Science and TechnologyTianjin300350China
| | - Chuancheng Jia
- Institute of Modern Optics and Center of Single Molecule SciencesNankai UniversityTianjin Key Laboratory of Micro‐scale Optical Information Science and TechnologyTianjin300350China
| | - Dong Xiang
- Institute of Modern Optics and Center of Single Molecule SciencesNankai UniversityTianjin Key Laboratory of Micro‐scale Optical Information Science and TechnologyTianjin300350China
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3
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Wang X, Zhu X, Wu P, Li Q, Li Z, Zhang X, Liu Z, Zhang Y, Du P. Differences in Kondo Splitting of Surface Quantum Systems Induced by Two Distinct Magnetic Tips: A Joint Method of DFT and HEOM. J Phys Chem A 2024; 128:4750-4760. [PMID: 38832647 DOI: 10.1021/acs.jpca.4c02067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
The interactions between a magnetic tip and local spin impurities initiate unconventional Kondo phenomena, such as asymmetric suppression or even splitting of the Kondo peak. However, a lack of realistic theoretical models and comprehensive explanations for this phenomenon persists due to the complexity of the interactions. This research employs a joint method of density functional theory (DFT) and hierarchical equation of motion (HEOM) to simulate and contrast the modulation of the spin state and Kondo behavior in the Fe/Cu(100) system with two distinct magnetic tips. A cobalt tip, possessing a larger magnetic moment, incites greater atomic displacement of the iron atom, more notable alterations in electronic structure, and enhanced charge transfer with the environment compared with the control process utilizing a nickel tip. Furthermore, the Kondo resonance undergoes asymmetric splitting as a result of the ferromagnetic correlation between the iron atom and the magnetic tip. The Co tip's higher spin polarization results in a wider spacing between the splitting peaks. This investigation underscores the precision of the DFT + HEOM approach in predicting complex quantum phenomena and explaining the underlying physical principles. This provides valuable theoretical support for developing more sophisticated quantum regulation experiments.
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Affiliation(s)
- Xiaoli Wang
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Xinru Zhu
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Ping Wu
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Qing Li
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Zhen Li
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Xiaolei Zhang
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Zhongmin Liu
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Yuexing Zhang
- Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, PR China
| | - Pengli Du
- College of Chemical Engineering, Qinghai University, Xining 810016, PR China
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4
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de Campos Ferreira R, Sagwal A, Doležal J, Canola S, Merino P, Neuman T, Švec M. Resonant Tip-Enhanced Raman Spectroscopy of a Single-Molecule Kondo System. ACS NANO 2024; 18:13164-13170. [PMID: 38711331 PMCID: PMC11112976 DOI: 10.1021/acsnano.4c02105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/11/2024] [Accepted: 04/24/2024] [Indexed: 05/08/2024]
Abstract
Tip-enhanced Raman spectroscopy (TERS) under ultrahigh vacuum and cryogenic conditions enables exploration of the relations between the adsorption geometry, electronic state, and vibrational fingerprints of individual molecules. TERS capability of reflecting spin states in open-shell molecular configurations is yet unexplored. Here, we use the tip of a scanning probe microscope to lift a perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecule from a metal surface to bring it into an open-shell spin one-half anionic state. We reveal a correlation between the appearance of a Kondo resonance in differential conductance spectroscopy and concurrent characteristic changes captured by the TERS measurements. Through a detailed investigation of various adsorbed and tip-contacted PTCDA scenarios, we infer that the Raman scattering on suspended PTCDA is resonant with a higher excited state. Theoretical simulation of the vibrational spectra enables a precise assignment of the individual TERS peaks to high-symmetry Ag modes, including the fingerprints of the observed spin state. These findings highlight the potential of TERS in capturing complex interactions between charge, spin, and photophysical properties in nanoscale molecular systems and suggest a pathway for designing single-molecule spin-optical devices.
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Affiliation(s)
| | - Amandeep Sagwal
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
- Faculty
of Mathematics and Physics, Charles University; Ke Karlovu 3, Praha 2 CZ12116. Czech Republic
| | - Jiří Doležal
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
- Institute
of Physics, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Sofia Canola
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
| | - Pablo Merino
- Instituto
de Ciencia de Materiales de Madrid; CSIC, Sor Juana Inés de la Cruz 3, Madrid E28049, Spain
| | - Tomáš Neuman
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
| | - Martin Švec
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences; Flemingovo náměstí 542/2. Praha 6 CZ16000, Czech Republic
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5
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Rabelo R, Toma L, Julve M, Lloret F, Pasán J, Cangussu D, Ruiz-García R, Cano J. How the spin state tunes the slow magnetic relaxation field dependence in spin crossover cobalt(II) complexes. Dalton Trans 2024; 53:5507-5520. [PMID: 38416047 DOI: 10.1039/d4dt00059e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
A novel family of cobalt(II) compounds with tridentate pyridine-2,6-diiminephenyl type ligands featuring electron-withdrawing substituents of general formula [Co(n-XPhPDI)2](ClO4)2·S [n-XPhPDI = 2,6-bis(N-n-halophenylformimidoyl)pyridine with n = 4 (1-3) and 3 (4); X = I (1), Br (2 and 4) and Cl (3); S = MeCN (1 and 2) and EtOAc (3)] has been synthesised and characterised by single-crystal X-ray diffraction, electron paramagnetic resonance, and static (dc) and dynamic (ac) magnetic measurements combined with theoretical calculations. The structures of 1-4 consist of mononuclear bis(chelating) cobalt(II) complex cations, [CoII(n-XPhPDI)2]2+, perchlorate anions, and acetonitrile (1 and 2) or ethyl acetate (3) molecules of crystallisation. This unique series of mononuclear six-coordinate octahedral cobalt(II) complexes displays both thermally-induced low-spin (LS)/high-spin (HS) transition and field-induced slow magnetic relaxation in both LS and HS states. A complete LS ↔ HS transition occurs for 1 and 2, while it is incomplete for 4, one-third of the complexes being HS at low temperatures. In contrast, 3 remains HS in all the temperature range. 1 and 2 show dual spin relaxation dynamics under the presence of an applied dc magnetic field (Hdc), with the occurrence of faster- (FR) and slower-relaxing (SR) processes at lower (Hdc = 1.0 kOe) and higher fields (Hdc = 2.5 kOe), respectively. On the contrary, 3 and 4 exhibit only SR and FR relaxations, regardless of Hdc. Overall, the distinct field-dependence of the single-molecule magnet (SMM) behaviour along with this family of spin-crossover (SCO) cobalt(II)-n-XPhPDI complexes is dominated by Raman mechanisms and, occasionally, with additional temperature-independent Intra-Kramer [LS or HS (D > 0)] or Quantum Tunneling of Magnetisation mechanisms [HS (D < 0)] also contributing.
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Affiliation(s)
- Renato Rabelo
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
- Instituto de Química, Universidade Federal de Goiás, Av. Esperança Campus Samambaia, Goiânia, GO, Brazil
| | - Luminita Toma
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Miguel Julve
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Francesc Lloret
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Jorge Pasán
- Laboratorio de Materiales para Análisis Químico (MAT4LL), Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, 38200 Tenerife, Spain
| | - Danielle Cangussu
- Instituto de Química, Universidade Federal de Goiás, Av. Esperança Campus Samambaia, Goiânia, GO, Brazil
| | - Rafael Ruiz-García
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Joan Cano
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
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Vilas-Varela M, Romero-Lara F, Vegliante A, Calupitan JP, Martínez A, Meyer L, Uriarte-Amiano U, Friedrich N, Wang D, Schulz F, Koval NE, Sandoval-Salinas ME, Casanova D, Corso M, Artacho E, Peña D, Pascual JI. On-Surface Synthesis and Characterization of a High-Spin Aza-[5]-Triangulene. Angew Chem Int Ed Engl 2023; 62:e202307884. [PMID: 37604782 DOI: 10.1002/anie.202307884] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
Triangulenes are a class of open-shell triangular graphene flakes with total spin increasing with their size. In the last years, on-surface-synthesis strategies have permitted fabricating and engineering triangulenes of various sizes and structures with atomic precision. However, direct proof of the increasing total spin with their size remains elusive. In this work, we report the combined in-solution and on-surface synthesis of a large nitrogen-doped triangulene (aza-[5]-triangulene) on a Au(111) surface, and the detection of its high-spin ground state. Bond-resolved scanning tunneling microscopy images uncovered radical states distributed along the zigzag edges, which were detected as weak zero-bias resonances in scanning tunneling spectra. These spectral features reveal the partial Kondo screening of a high-spin state. Through a combination of several simulation tools, we find that the observed distribution of radical states is explained by a quintet ground state (S=2), instead of the quartet state (S=3/2) expected for the neutral species. This confirms that electron transfer to the metal substrate raises the spin of the ground state. We further provide a qualitative description of the change of (anti)aromaticity introduced by N-substitution, and its role in the charge stabilization on a surface, resulting in an S=2 aza-triangulene on Au(111).
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Affiliation(s)
- Manuel Vilas-Varela
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-, Santiago de Compostela, Spain
| | | | | | - Jan Patrick Calupitan
- Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, 20018, Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018, Donostia-San Sebastián, Spain
| | - Adrián Martínez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-, Santiago de Compostela, Spain
| | - Lorenz Meyer
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
| | | | | | - Dongfei Wang
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
| | - Fabian Schulz
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
| | | | | | - David Casanova
- Donostia International Physics Center (DIPC), 20018, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Martina Corso
- Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, 20018, Donostia-San Sebastián, Spain
| | - Emilio Artacho
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
- Theory of Condensed Matter, Cavendish Laboratory, University of Cambridge, J. J. Thomson Ave., Cambridge, CB3 0HE, UK
| | - Diego Peña
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-, Santiago de Compostela, Spain
| | - José Ignacio Pascual
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
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7
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Trang CDM, Saal T, Inkpen MS. Methyldisulfide groups enable the direct connection of air-stable metal bis(terpyridine) complexes to gold surfaces. Dalton Trans 2023; 52:7836-7842. [PMID: 37218422 PMCID: PMC10330856 DOI: 10.1039/d3dt00955f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We show that a new terpyridine ligand comprising a directly-connected methyldisulfide group (tpySSMe) can be used to prepare a modular series of metal bis(terpyidine) complexes, [M(tpySSMe)2](PF6)2 (M = Fe, Co, Zn), suitable for the functionalization of metal surfaces. Critically, we find these complexes are air-stable in solution for >7 d, in stark contrast to their thiol-substituted analogues, [M(tpySH)2](PF6)2 (M = Fe, Co), which decompose in <1 d. While CoSH has previously been utilized in several important studies, we explicitly detail its synthesis and characterization here for the first time. We subsequently probe the electrochemical properties of [M(tpySSMe)2](PF6)2 in solution, showing that the (electro)chemical reactions associated with disulfide reduction significantly increase the complexity of the voltammetric response. In preliminary surface voltammetry studies, we confirm that CoSS and FeSS form solution-stable self-assembled monolayers (SAMs) on gold with comparable electrochemical properties to those formed from CoSH. Taken together, this work provides a robust foundation for future studies of this prominent class of complexes as redox-active components of SAMs or single-molecule junctions.
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Affiliation(s)
- Christina D M Trang
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
| | - Thomas Saal
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
| | - Michael S Inkpen
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
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8
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Rahman MT, Jahangir Alam M, Ahmed N, Roy DC, Sultana P. Trend of risk and correlates of under-five child undernutrition in Bangladesh: an analysis based on Bangladesh Demographic and Health Survey data, 2007-2017/2018. BMJ Open 2023; 13:e070480. [PMID: 37308267 PMCID: PMC10277110 DOI: 10.1136/bmjopen-2022-070480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 05/31/2023] [Indexed: 06/14/2023] Open
Abstract
OBJECTIVES The objectives of this study are to identify the trend of undernutrition risk among under-five children (U5C) in Bangladesh and the trend of its correlates. DESIGN Multiple cross-sectional data sets from different time points were used. SETTING Nationally representative Bangladesh Demographic and Health Surveys (BDHSs) were conducted in 2007, 2011, 2014 and 2017/2018. PARTICIPANTS In the BDHSs, the sample sizes for ever-married women (age: 15-49 years) were 5300 in 2007, 7647 in 2011, 6965 in 2014 and 7902 in 2017/2018. OUTCOMES Extant indicators of undernutrition (stunted, wasted and underweight) have been considered as the outcome variables. MATERIALS AND METHODS Descriptive statistics, bivariate analysis and factor loadings from factor analysis have been used to determine the prevalence of undernutrition over the years and find the trend of risk and its correlates. RESULTS Risks of stunting among the U5C were 41.70%, 40.67%, 36.57% and 31.14%; that of wasting were 16.94%, 15.48%, 14.43% and 8.44%; and that of underweight were 39.79%, 35.80%, 32.45% and 22.46% in 2007, 2011, 2014 and 2017/2018, respectively. From the factor analysis, it has been found that the top five potential correlates of undernutrition are the wealth index, the education of the father and mother, the frequency of antenatal visits during pregnancy, the father's occupation and/or the type of place of residence in the last four consecutive surveys. CONCLUSION This study helps us gain a better understanding of the impact of the top correlates on child undernutrition. To accelerate the reduction of child undernutrition more by 2030, Government and non-government organisations should focus on improving education and household income-generating activities among poor households and raising awareness among women about the importance of receiving antenatal care during pregnancy.
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Affiliation(s)
- Md Tahidur Rahman
- Department of Statistics, Islamic University, Kushtia, Bangladesh
- Department of Statistics, University of Rajshahi, Rajshahi, Bangladesh
| | - Md Jahangir Alam
- Department of Statistics, University of Rajshahi, Rajshahi, Bangladesh
| | - Noyon Ahmed
- Department of Statistics, University of Rajshahi, Rajshahi, Bangladesh
| | - Dulal Chandra Roy
- Department of Statistics, University of Rajshahi, Rajshahi, Bangladesh
| | - Papia Sultana
- Department of Statistics, University of Rajshahi, Rajshahi, Bangladesh
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9
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Li T, Bandari VK, Schmidt OG. Molecular Electronics: Creating and Bridging Molecular Junctions and Promoting Its Commercialization. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209088. [PMID: 36512432 DOI: 10.1002/adma.202209088] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/28/2022] [Indexed: 06/02/2023]
Abstract
Molecular electronics is driven by the dream of expanding Moore's law to the molecular level for next-generation electronics through incorporating individual or ensemble molecules into electronic circuits. For nearly 50 years, numerous efforts have been made to explore the intrinsic properties of molecules and develop diverse fascinating molecular electronic devices with the desired functionalities. The flourishing of molecular electronics is inseparable from the development of various elegant methodologies for creating nanogap electrodes and bridging the nanogap with molecules. This review first focuses on the techniques for making lateral and vertical nanogap electrodes by breaking, narrowing, and fixed modes, and highlights their capabilities, applications, merits, and shortcomings. After summarizing the approaches of growing single molecules or molecular layers on the electrodes, the methods of constructing a complete molecular circuit are comprehensively grouped into three categories: 1) directly bridging one-molecule-electrode component with another electrode, 2) physically bridging two-molecule-electrode components, and 3) chemically bridging two-molecule-electrode components. Finally, the current state of molecular circuit integration and commercialization is discussed and perspectives are provided, hoping to encourage the community to accelerate the realization of fully scalable molecular electronics for a new era of integrated microsystems and applications.
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Affiliation(s)
- Tianming Li
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
| | - Vineeth Kumar Bandari
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
| | - Oliver G Schmidt
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
- Nanophysics, Dresden University of Technology, 01069, Dresden, Germany
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10
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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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11
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Wang X, Zhuang Q, Wu P, Liu L, Wang F, Zhang X, Li X, Zheng X. Tweezer-like magnetic tip control of the local spin state in the FeOEP/Pb(111) adsorption system: a preliminary exploration based on first-principles calculations. NANOSCALE 2023; 15:2369-2376. [PMID: 36648279 DOI: 10.1039/d2nr04379c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The magnetic interactions between the spin-polarized scanning tunnelling microscopy (SP-STM) tip and the localized spin impurities lead to various forms of the Kondo effect. Although these intriguing phenomena enrich Kondo physics, detailed theoretical simulations and explanations are still lacking due to the rather complex formation mechanisms. Here, by combining density functional theory (DFT), complete active space self-consistent field (CASSCF) theory, and hierarchical equations of motion (HEOM) methods, we perform first-principles-based simulation to elaborate the regulation process of the magnetic Co-tip on the spin state and transport behaviour of FeOEP/Pb(111) system. Compared with the non-magnetic tip, the stronger interaction between the magnetic tip and FeOEP molecule results in a more drastic deformation of the molecular structure with more electron transfer from the local environment to Fe-3d orbitals. The magnetic anisotropy of FeOEP changes very drastically from positive values in the tunnelling region to negative values in the contact region. The ferromagnetic electron correlation between the magnetic tip and the molecule induces an asymmetric Kondo line-shape near the Fermi level. This work highlights that the DFT + CASSCF + HEOM approach can not only predict complex quantum phenomena and explain underlying physical mechanisms, but also facilitate the design of more fascinating quantum control experiments.
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Affiliation(s)
- Xiaoli Wang
- College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, China
| | - Qingfeng Zhuang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Ping Wu
- College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, China
| | - Leifang Liu
- College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, China
| | - Fang Wang
- College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, China
| | - Xiaolei Zhang
- College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, China
| | - Xiangyang Li
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xiao Zheng
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
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12
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Zhang D, Zuo L, Ye L, Chen ZH, Wang Y, Xu RX, Zheng X, Yan Y. Hierarchical equations of motion approach for accurate characterization of spin excitations in quantum impurity systems. J Chem Phys 2023; 158:014106. [PMID: 36610957 DOI: 10.1063/5.0131739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Recent technological advancement in scanning tunneling microscopes has enabled the measurement of spin-field and spin-spin interactions in single atomic or molecular junctions with an unprecedentedly high resolution. Theoretically, although the fermionic hierarchical equations of motion (HEOM) method has been widely applied to investigate the strongly correlated Kondo states in these junctions, the existence of low-energy spin excitations presents new challenges to numerical simulations. These include the quest for a more accurate and efficient decomposition for the non-Markovian memory of low-temperature environments and a more careful handling of errors caused by the truncation of the hierarchy. In this work, we propose several new algorithms, which significantly enhance the performance of the HEOM method, as exemplified by the calculations on systems involving various types of low-energy spin excitations. Being able to characterize both the Kondo effect and spin excitation accurately, the HEOM method offers a sophisticated and versatile theoretical tool, which is valuable for the understanding and even prediction of the fascinating quantum phenomena explored in cutting-edge experiments.
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Affiliation(s)
- Daochi Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Lijun Zuo
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Lyuzhou Ye
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zi-Hao Chen
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yao Wang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Rui-Xue Xu
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiao Zheng
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - YiJing Yan
- Hefei National Research Center for Physical Sciences at the Microscale and iChEM, University of Science and Technology of China, Hefei, Anhui 230026, China
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13
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Zuo L, Zhuang Q, Ye L, Yan Y, Zheng X. Unveiling the Decisive Factor for the Sharp Transition in the Scanning Tunneling Spectroscopy of a Single Nickelocene Molecule. J Phys Chem Lett 2022; 13:11262-11270. [PMID: 36448930 DOI: 10.1021/acs.jpclett.2c03168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Scanning tunneling microscopy (STM) has been utilized to realize the precise measurement and control of local spin states. Experiments have demonstrated that when a nickelocene (Nc) molecule is attached to the apex of an STM tip, the dI/dV spectra exhibit a sharp or a smooth transition when the tip is displaced toward the substrate. However, what leads to the two distinct types of transitions remains unclear, and more intriguingly, the physical origin of the abrupt change in the line shape of dI/dV spectra remains unclear. To clarify these intriguing issues, we perform first-principles-based simulations on the STM tip control process for the Cu tip/Nc/Cu(100) junction. In particular, we find that the suddenly enhanced hybridization between the d orbitals on the Ni ion and the metallic bands in the substrate leads to Kondo correlation overwhelming spin excitation, which is the main cause of the sharp transition in the dI/dV spectra observed experimentally.
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Affiliation(s)
- Lijun Zuo
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Qingfeng Zhuang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Lyuzhou Ye
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - YiJing Yan
- Hefei National Research Center for Physical Sciences at the Microscale and iChEM, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiao Zheng
- Department of Chemistry, Fudan University, Shanghai 200433, China
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14
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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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15
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Conductance Modulation in an α-Terthiophene Molecular Junction Characterized by Surface-Enhanced Raman Scattering. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2022. [DOI: 10.1380/ejssnt.2023-004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Baum TY, Fernández S, Peña D, van der Zant HSJ. Magnetic Fingerprints in an All-Organic Radical Molecular Break Junction. NANO LETTERS 2022; 22:8086-8092. [PMID: 36206381 PMCID: PMC9614975 DOI: 10.1021/acs.nanolett.2c02326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/05/2022] [Indexed: 05/25/2023]
Abstract
Polycyclic aromatic hydrocarbons radicals are organic molecules with a nonzero total magnetic moment. Here, we report on charge-transport experiments with bianthracene-based radicals using a mechanically controlled break junction technique at low temperatures (6 K). The conductance spectra demonstrate that the magnetism of the diradical is preserved in solid-state devices and that it manifests itself either in the form of a Kondo resonance or inelastic electron tunneling spectroscopy signature caused by spin-flip processes. The magnetic fingerprints depend on the exact configuration of the molecule in the junction; this picture is supported by reference measurements on a radical molecule with the same backbone but with one free spin, in which only Kondo anomalies are observed. The results show that the open-shell structures based on the bianthracene core are interesting systems to study spin-spin interactions in solid-state devices, and this may open the way to control them either electrically or by mechanical strain.
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Affiliation(s)
- Thomas Y. Baum
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJDelft, The Netherlands
| | - Saleta Fernández
- Centro
Singular de Investigación en Química Biolóxica
e Materiais Moleculares (CiQUS) and Departamento de Química
Orgánica, Universidade de Santiago
de Compostela, Santiago
de Compostela, Spain15782
| | - Diego Peña
- Centro
Singular de Investigación en Química Biolóxica
e Materiais Moleculares (CiQUS) and Departamento de Química
Orgánica, Universidade de Santiago
de Compostela, Santiago
de Compostela, Spain15782
| | - Herre S. J. van der Zant
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJDelft, The Netherlands
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17
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Shin J, Eo JS, Jeon T, Lee T, Wang G. Advances of Various Heterogeneous Structure Types in Molecular Junction Systems and Their Charge Transport Properties. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202399. [PMID: 35975456 PMCID: PMC9596861 DOI: 10.1002/advs.202202399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/11/2022] [Indexed: 05/31/2023]
Abstract
Molecular electronics that can produce functional electronic circuits using a single molecule or molecular ensemble remains an attractive research field because it not only represents an essential step toward realizing ultimate electronic device scaling but may also expand our understanding of the intrinsic quantum transports at the molecular level. Recently, in order to overcome the difficulties inherent in the conventional approach to studying molecular electronics and developing functional device applications, this field has attempted to diversify the electrical characteristics and device architectures using various types of heterogeneous structures in molecular junctions. This review summarizes recent efforts devoted to functional devices with molecular heterostructures. Diverse molecules and materials can be combined and incorporated in such two- and three-terminal heterojunction structures, to achieve desirable electronic functionalities. The heterojunction structures, charge transport mechanisms, and possible strategies for implementing electronic functions using various hetero unit materials are presented sequentially. In addition, the applicability and merits of molecular heterojunction structures, as well as the anticipated challenges associated with their implementation in device applications are discussed and summarized. This review will contribute to a deeper understanding of charge transport through molecular heterojunction, and it may pave the way toward desirable electronic functionalities in molecular electronics applications.
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Affiliation(s)
- Jaeho Shin
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
- Department of ChemistryRice University6100 Main StreetHoustonTexas77005United States
| | - Jung Sun Eo
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
| | - Takgyeong Jeon
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
| | - Takhee Lee
- Department of Physics and AstronomyInstitute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Gunuk Wang
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
- Department of Integrative Energy EngineeringKorea UniversitySeoul02841Korea
- Center for Neuromorphic EngineeringKorea Institute of Science and TechnologySeoul02792Korea
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18
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Zhou WH, Zhang J, Nan N, Li W, He ZD, Zhu ZW, Wu YP, Xiong YC. Correlation anisotropy driven Kosterlitz-Thouless-type quantum phase transition in a Kondo simulator. Phys Chem Chem Phys 2022; 24:20040-20049. [PMID: 35833449 DOI: 10.1039/d2cp01668k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The precise manipulation of the quantum states of individual atoms/molecules adsorbed on metal surfaces is one of the most exciting frontiers in nanophysics, enabling us to realize novel single molecular logic devices and quantum information processing. Herein, by modeling an iron phthalocyanine molecule adsorbed on the Au(111) surface with a two-impurity Anderson model, we demonstrate that the quantum states of such a system could be adjusted by the uniaxial magnetic anisotropy Dz. For negative Dz, the ground state is dominated by a parallel configuration of the z component of local spins, whereas it turns to be an antiparallel one when Dz becomes positive. Interestingly, we found that these two phases are separated by a Kosterlitz-Thouless-type quantum phase transition, which is confirmed by the critical behaviors of the transmission coefficient and the local magnetic moment. Both phases are associated with spin correlation anisotropy, thus move against the Kondo effect. When the external magnetic field is applied, it first plays a role in compensating for the effect of Dz, and then it contributes significantly to the Zeeman effect for positive Dz, accompanied by the reappearance and the splitting of the Kondo peak, respectively. For fixed negative Dz, only the Zeeman behavior is revealed. Our results provide deep insights into the manipulation of the quantum phase within a single molecular junction.
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Affiliation(s)
- Wang-Huai Zhou
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China. .,Shiyan Industrial Technology Research Institute of Chinese Academy of Engineering, Shiyan 442002, People's Republic of China
| | - Jun Zhang
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China. .,Shiyan Industrial Technology Research Institute of Chinese Academy of Engineering, Shiyan 442002, People's Republic of China
| | - Nan Nan
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China. .,Shiyan Industrial Technology Research Institute of Chinese Academy of Engineering, Shiyan 442002, People's Republic of China
| | - Wei Li
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China. .,Shiyan Industrial Technology Research Institute of Chinese Academy of Engineering, Shiyan 442002, People's Republic of China
| | - Ze-Dong He
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China.
| | - Zhan-Wu Zhu
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China.
| | - Yun-Pei Wu
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China.
| | - Yong-Chen Xiong
- School of Mathematics, Physics and Optoelectronic Engineering, and Collaborative Innovation Center for Optoelectronic Technology, Hubei University of Automotive Technology, Shiyan, Hubei, P. R. China. .,Shiyan Industrial Technology Research Institute of Chinese Academy of Engineering, Shiyan 442002, People's Republic of China
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19
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Biswas K, Urbani M, Sánchez-Grande A, Soler-Polo D, Lauwaet K, Matěj A, Mutombo P, Veis L, Brabec J, Pernal K, Gallego JM, Miranda R, Écija D, Jelínek P, Torres T, Urgel JI. Interplay between π-Conjugation and Exchange Magnetism in One-Dimensional Porphyrinoid Polymers. J Am Chem Soc 2022; 144:12725-12731. [PMID: 35817408 PMCID: PMC9305978 DOI: 10.1021/jacs.2c02700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The synthesis of novel polymeric materials with porphyrinoid compounds as key components of the repeating units attracts widespread interest from several scientific fields in view of their extraordinary variety of functional properties with potential applications in a wide range of highly significant technologies. The vast majority of such polymers present a closed-shell ground state, and, only recently, as the result of improved synthetic strategies, the engineering of open-shell porphyrinoid polymers with spin delocalization along the conjugation length has been achieved. Here, we present a combined strategy toward the fabrication of one-dimensional porphyrinoid-based polymers homocoupled via surface-catalyzed [3 + 3] cycloaromatization of isopropyl substituents on Au(111). Scanning tunneling microscopy and noncontact atomic force microscopy describe the thermal-activated intra- and intermolecular oxidative ring closure reactions as well as the controlled tip-induced hydrogen dissociation from the porphyrinoid units. In addition, scanning tunneling spectroscopy measurements, complemented by computational investigations, reveal the open-shell character, that is, the antiferromagnetic singlet ground state (S = 0) of the formed polymers, characterized by singlet-triplet inelastic excitations observed between spins of adjacent porphyrinoid units. Our approach sheds light on the crucial relevance of the π-conjugation in the correlations between spins, while expanding the on-surface synthesis toolbox and opening avenues toward the synthesis of innovative functional nanomaterials with prospects in carbon-based spintronics.
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Affiliation(s)
- Kalyan Biswas
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain
| | - Maxence Urbani
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain
| | - Ana Sánchez-Grande
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain
| | - Diego Soler-Polo
- Institute of Physics of the Czech Academy of Science, Praha 162 00, Czech Republic
| | - Koen Lauwaet
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain
| | - Adam Matěj
- Institute of Physics of the Czech Academy of Science, Praha 162 00, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Olomouc 783 71, Czech Republic
| | - Pingo Mutombo
- Institute of Physics of the Czech Academy of Science, Praha 162 00, Czech Republic
| | - Libor Veis
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Prague 182 00, Czech Republic
| | - Jiri Brabec
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Prague 182 00, Czech Republic
| | - Katarzyna Pernal
- Institute of Physics, Lodz University of Technology, Lodz 90-924, Poland
| | - José M Gallego
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, Madrid 28049, Spain
| | - Rodolfo Miranda
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain.,Departamento de Física de La Materia Condensada, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - David Écija
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain
| | - Pavel Jelínek
- Institute of Physics of the Czech Academy of Science, Praha 162 00, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Olomouc 783 71, Czech Republic
| | - Tomás Torres
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain.,Departamento de Química Orgánica and Institute for Advanced Research in Chemistry (IAdChem), Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - José I Urgel
- IMDEA Nanoscience, C/ Faraday 9, Campus de Cantoblanco, Madrid 28049, Spain
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20
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Li P, Zhou L, Zhao C, Ju H, Gao Q, Si W, Cheng L, Hao J, Li M, Chen Y, Jia C, Guo X. Single-molecule nano-optoelectronics: insights from physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:086401. [PMID: 35623319 DOI: 10.1088/1361-6633/ac7401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Single-molecule optoelectronic devices promise a potential solution for miniaturization and functionalization of silicon-based microelectronic circuits in the future. For decades of its fast development, this field has made significant progress in the synthesis of optoelectronic materials, the fabrication of single-molecule devices and the realization of optoelectronic functions. On the other hand, single-molecule optoelectronic devices offer a reliable platform to investigate the intrinsic physical phenomena and regulation rules of matters at the single-molecule level. To further realize and regulate the optoelectronic functions toward practical applications, it is necessary to clarify the intrinsic physical mechanisms of single-molecule optoelectronic nanodevices. Here, we provide a timely review to survey the physical phenomena and laws involved in single-molecule optoelectronic materials and devices, including charge effects, spin effects, exciton effects, vibronic effects, structural and orbital effects. In particular, we will systematically summarize the basics of molecular optoelectronic materials, and the physical effects and manipulations of single-molecule optoelectronic nanodevices. In addition, fundamentals of single-molecule electronics, which are basic of single-molecule optoelectronics, can also be found in this review. At last, we tend to focus the discussion on the opportunities and challenges arising in the field of single-molecule optoelectronics, and propose further potential breakthroughs.
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Affiliation(s)
- Peihui Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Zhou
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Cong Zhao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Hongyu Ju
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, People's Republic of China
| | - Qinghua Gao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Wei Si
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Cheng
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Jie Hao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Mengmeng Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Yijian Chen
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Chuancheng Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
| | - Xuefeng Guo
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
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21
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Kuppusamy SK, Mizuno A, García-Fuente A, van der Poel S, Heinrich B, Ferrer J, van der Zant HSJ, Ruben M. Spin-Crossover in Supramolecular Iron(II)-2,6-bis(1 H-Pyrazol-1-yl)pyridine Complexes: Toward Spin-State Switchable Single-Molecule Junctions. ACS OMEGA 2022; 7:13654-13666. [PMID: 35559184 PMCID: PMC9088905 DOI: 10.1021/acsomega.1c07217] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/21/2022] [Indexed: 05/27/2023]
Abstract
Spin-crossover (SCO) active iron(II) complexes are an integral class of switchable and bistable molecular materials. Spin-state switching properties of the SCO complexes have been studied in the bulk and single-molecule levels to progress toward fabricating molecule-based switching and memory elements. Supramolecular SCO complexes featuring anchoring groups for metallic electrodes, for example, gold (Au), are ideal candidates to study spin-state switching at the single-molecule level. In this study, we report on the spin-state switching characteristics of supramolecular iron(II) complexes 1 and 2 composed of functional 4-([2,2'-bithiophen]-5-ylethynyl)-2,6-di(1H-pyrazol-1-yl)pyridine (L1) and 4-(2-(5-(5-hexylthiophen-2-yl)thiophen-2-yl)ethynyl)-2,6-di(1H-pyrazol-1-yl)pyridine (L2) ligands, respectively. Density functional theory (DFT) studies revealed stretching-induced spin-state switching in a molecular junction composed of complex 1, taken as a representative example, and gold electrodes. Single-molecule conductance traces revealed the unfavorable orientation of the complexes in the junctions to demonstrate the spin-state dependence of the conductance.
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Affiliation(s)
- Senthil Kumar Kuppusamy
- Institute
for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Asato Mizuno
- Institute
of Nanotechnology, Karlsruhe Institute of
Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Amador García-Fuente
- Departamento
de Física, Universidad de Oviedo, ES-33007 Oviedo, Spain
- Centro
de Investigación en Nanotecnología y Nanomateriales
(CINN, CSIC), El Entrego ES-33940, Spain
| | - Sebastiaan van der Poel
- Kavli
Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Benoît Heinrich
- Institut
de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg,
23, rue du Loess, BP 43, 67034 cedex
2 Strasbourg, France
| | - Jaime Ferrer
- Departamento
de Física, Universidad de Oviedo, ES-33007 Oviedo, Spain
- Centro
de Investigación en Nanotecnología y Nanomateriales
(CINN, CSIC), El Entrego ES-33940, Spain
| | - Herre S. J. van der Zant
- Kavli
Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands
| | - Mario Ruben
- Institute
for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Institute
of Nanotechnology, Karlsruhe Institute of
Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Université
de Strasbourg (Unistra), Institute de Science et d′Ingénierie
Supramoléculaire (ISIS), Centre Européen de Science
Quantique (CESQ), 8,
Allée Gaspard Monge, F-67000 Strasbourg, France
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22
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Bao L, Huang L, Guo H, Gao HJ. Construction and physical properties of low-dimensional structures for nanoscale electronic devices. Phys Chem Chem Phys 2022; 24:9082-9117. [PMID: 35383791 DOI: 10.1039/d1cp05981e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over the past decades, construction of nanoscale electronic devices with novel functionalities based on low-dimensional structures, such as single molecules and two-dimensional (2D) materials, has been rapidly developed. To investigate their intrinsic properties for versatile functionalities of nanoscale electronic devices, it is crucial to precisely control the structures and understand the physical properties of low-dimensional structures at the single atomic level. In this review, we provide a comprehensive overview of the construction of nanoelectronic devices based on single molecules and 2D materials and the investigation of their physical properties. For single molecules, we focus on the construction of single-molecule devices, such as molecular motors and molecular switches, by precisely controlling their self-assembled structures on metal substrates and charge transport properties. For 2D materials, we emphasize their spin-related electrical transport properties for spintronic device applications and the role that interfaces among 2D semiconductors, contact electrodes, and dielectric substrates play in the electrical performance of electronic, optoelectronic, and memory devices. Finally, we discuss the future research direction in this field, where we can expect a scientific breakthrough.
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Affiliation(s)
- Lihong Bao
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, P. R. China
| | - Li Huang
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
| | - Hui Guo
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
| | - Hong-Jun Gao
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, P. R. China
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23
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Hsu C, Costi TA, Vogel D, Wegeberg C, Mayor M, van der Zant HSJ, Gehring P. Magnetic-Field Universality of the Kondo Effect Revealed by Thermocurrent Spectroscopy. PHYSICAL REVIEW LETTERS 2022; 128:147701. [PMID: 35476482 DOI: 10.1103/physrevlett.128.147701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
Probing the universal low-temperature magnetic-field scaling of Kondo-correlated quantum dots via electrical conductance has proved to be experimentally challenging. Here, we show how to probe this in nonlinear thermocurrent spectroscopy applied to a molecular quantum dot in the Kondo regime. Our results demonstrate that the bias-dependent thermocurrent is a sensitive probe of universal Kondo physics, directly measures the splitting of the Kondo resonance in a magnetic field, and opens up possibilities for investigating nanosystems far from thermal and electrical equilibrium.
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Affiliation(s)
- Chunwei Hsu
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands
| | - Theo A Costi
- Peter Grünberg Institut, Forschungszentrum Jülich, 52425 Jülich, Germany
- Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - David Vogel
- Department of Chemistry, University of Basel, St. Johanns Ring 19, 4056 Basel, Switzerland
| | - Christina Wegeberg
- Department of Chemistry, University of Basel, St. Johanns Ring 19, 4056 Basel, Switzerland
| | - Marcel Mayor
- Department of Chemistry, University of Basel, St. Johanns Ring 19, 4056 Basel, Switzerland
- Institute for Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany
- Lehn Institute of Functional Materials (LIFM), School of Chemistry, Sun Yat-Sen University (SYSU), 510275 Guangzhou, China
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands
| | - Pascal Gehring
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands
- IMCN/NAPS, Université Catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium
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24
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Dan X, Xu M, Yan Y, Shi Q. Generalized master equation for charge transport in a molecular junction: Exact memory kernels and their high order expansion. J Chem Phys 2022; 156:134114. [PMID: 35395901 DOI: 10.1063/5.0086663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We derive a set of generalized master equations (GMEs) to study charge transport dynamics in molecular junctions using the Nakajima-Zwanzig-Mori projection operator approach. In the new GME, time derivatives of population on each quantum state of the molecule, as well as the tunneling current, are calculated as the convolution of time non-local memory kernels with populations on all system states. The non-Markovian memory kernels are obtained by combining the hierarchical equations of motion (HEOM) method and a previous derived Dyson relation for the exact kernel. A perturbative expansion of these memory kernels is then calculated using the extended HEOM developed in our previous work [M. Xu et al., J. Chem. Phys. 146, 064102 (2017)]. By using the resonant level model and the Anderson impurity model, we study properties of the exact memory kernels and analyze convergence properties of their perturbative expansions with respect to the system-bath coupling strength and the electron-electron repulsive energy. It is found that exact memory kernels calculated from HEOM exhibit short memory times and decay faster than the population and current dynamics. The high order perturbation expansion of the memory kernels can give converged results in certain parameter regimes. The Padé and Landau-Zener resummation schemes are also found to give improved results over low order perturbation theory.
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Affiliation(s)
- Xiaohan Dan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meng Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaming Yan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiang Shi
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China
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25
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Xie X, Li P, Xu Y, Zhou L, Yan Y, Xie L, Jia C, Guo X. Single-Molecule Junction: A Reliable Platform for Monitoring Molecular Physical and Chemical Processes. ACS NANO 2022; 16:3476-3505. [PMID: 35179354 DOI: 10.1021/acsnano.1c11433] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Monitoring and manipulating the physical and chemical behavior of single molecules is an important development direction of molecular electronics that aids in understanding the molecular world at the single-molecule level. The electrical detection platform based on single-molecule junctions can monitor physical and chemical processes at the single-molecule level with a high temporal resolution, stability, and signal-to-noise ratio. Recently, the combination of single-molecule junctions with different multimodal control systems has been widely used to explore significant physical and chemical phenomena because of its powerful monitoring and control capabilities. In this review, we focus on the applications of single-molecule junctions in monitoring molecular physical and chemical processes. The methods developed for characterizing single-molecule charge transfer and spin characteristics as well as revealing the corresponding intrinsic mechanisms are introduced. Dynamic detection and regulation of single-molecule conformational isomerization, intermolecular interactions, and chemical reactions are also discussed in detail. In addition to these dynamic investigations, this review discusses the open challenges of single-molecule detection in the fields of physics and chemistry and proposes some potential applications in this field.
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Affiliation(s)
- Xinmiao Xie
- Center for Molecular Systems and Organic Devices (CMSOD), Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing 210023, PR China
| | - Peihui Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, PR China
| | - Yanxia Xu
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, PR China
| | - Li Zhou
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, PR China
| | - Yong Yan
- Center for Molecular Systems and Organic Devices (CMSOD), Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing 210023, PR China
| | - Linghai Xie
- Center for Molecular Systems and Organic Devices (CMSOD), Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing 210023, PR China
| | - Chuancheng Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, PR China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, PR China
| | - Xuefeng Guo
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, PR China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, PR China
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26
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Zhuang Q, Wang X, Ye L, Yan Y, Zheng X. Origin of Asymmetric Splitting of Kondo Peak in Spin-Polarized Scanning Tunneling Spectroscopy: Insights from First-Principles-Based Simulations. J Phys Chem Lett 2022; 13:2094-2100. [PMID: 35225612 DOI: 10.1021/acs.jpclett.2c00228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The spin-polarized scanning tunneling microscope (SP-STM) has served as a versatile tool for probing and manipulating the spintronic properties of atomic and molecular devices with high precision. The interplay between the local spin state and its surrounding magnetic environment significantly affects the transport behavior of the device. Particularly, in the contact regime, the strong hybridization between the SP-STM tip and the magnetic atom or molecule could give rise to unconventional Kondo resonance signatures in the differential conductance (dI/dV) spectra. This poses challenges for the simulation of a realistic tip control process. By combining the density functional theory and the hierarchical equations of motion methods, we achieve first-principles-based simulation of the control of a Ni-tip/Co/Cu(100) junction in both the tunneling and contact regimes. The calculated dI/dV spectra reproduce faithfully the experimental data. A cotunneling mechanism is proposed to elucidate the physical origin of the observed unconventional Kondo signatures.
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Affiliation(s)
- Qingfeng Zhuang
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaoli Wang
- School of Chemistry and Chemical Engineering, Dezhou University, Dezhou, Shandong 253023, China
| | - Lyuzhou Ye
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - YiJing Yan
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiao Zheng
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei, Anhui 230026, China
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27
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Liu B, Miao G, Zhong W, Huang X, Su N, Guo J, Wang W. Manipulating the Electronic and Magnetic Properties of Coordinated Nickel Atoms in Metal-Organic Frameworks by Hydrogenation. ACS NANO 2022; 16:2147-2153. [PMID: 35041376 DOI: 10.1021/acsnano.1c07902] [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
In the pursuit of manipulating the properties of single atoms, the surface-supported metal-organic frameworks (MOFs) provide us opportunities to individually address the electronic and magnetic properties of coordinated metal atoms by scanning tunneling microscopy. Recently, we have synthesized Ni-TPyP (TPyP = 5,10,15,20-tetra-(4-pyridyl) porphyrin) networks with dinuclear Ni centers on a Au(111) surface, in which the top-Ni atoms are sitting above the molecular plane. Here, we investigate the top-Ni atoms and their hydrogenated derivatives by low-temperature scanning tunneling microscopy and spectroscopy, and show that the electronic and magnetic states of top-Ni atoms can be manipulated by hydrogen adsorption. Specifically, by fitting the spin-flip spectra in vertical magnetic field, we find the spin state of top-Ni atoms is tuned from S = 1/2 to S = 1 by attaching one H atom and S = 3/2 by attaching two H atoms. Our work demonstrates atomic-scale control over the electronic and magnetic properties of coordinated metal atoms in a surface-supported MOF.
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Affiliation(s)
- Bing Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Guangyao Miao
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Weiliang Zhong
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaochun Huang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Nuoyu Su
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiandong Guo
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Weihua Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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28
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Nan N, Zhou WH, Zhang J, Li W, Yang JT, Chen J, Xiong YC, Tan G. Phase transitions induced by exchange coupling, magnetic field, and temperature in a strongly correlated molecular trimer with triangular topology. Phys Chem Chem Phys 2022; 24:22546-22556. [DOI: 10.1039/d2cp03313e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Regulating the physical properties such as the quantum phase and the Kondo effect of molecular electronic devices near critical points may play a key role in increasing the robustness of...
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29
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Žitko R, Blesio GG, Manuel LO, Aligia AA. Iron phthalocyanine on Au(111) is a "non-Landau" Fermi liquid. Nat Commun 2021; 12:6027. [PMID: 34654828 PMCID: PMC8521586 DOI: 10.1038/s41467-021-26339-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 09/28/2021] [Indexed: 11/24/2022] Open
Abstract
The paradigm of Landau’s Fermi liquid theory has been challenged with the finding of a strongly interacting Fermi liquid that cannot be adiabatically connected to a non-interacting system. A spin-1 two-channel Kondo impurity with anisotropy D has a quantum phase transition between two topologically different Fermi liquids with a peak (dip) in the Fermi level for D < Dc (D > Dc). Extending this theory to general multi-orbital problems with finite magnetic field, we reinterpret in a unified and consistent fashion several experimental studies of iron phthalocyanine molecules on Au(111) that were previously described in disconnected and conflicting ways. The differential conductance shows a zero-bias dip that widens when the molecule is lifted from the surface (reducing the Kondo couplings) and is transformed continuously into a peak under an applied magnetic field. We reproduce all features and propose an experiment to induce the topological transition. Single molecules on metal surfaces are paradigmatic systems for the study of many-body phenomena. Here, the authors show that several spectroscopic experiments on iron phthalocyanine on Au(111) surface can be described in a unified way in terms of a strongly interacting topologically non-trivial (non-Landau) Fermi liquid.
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Affiliation(s)
- R Žitko
- Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia. .,Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000, Ljubljana, Slovenia.
| | - G G Blesio
- Jožef Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia.,Instituto de Física Rosario (CONICET) and Universidad Nacional de Rosario, Bv. 27 de Febrero 210 bis, 2000, Rosario, Argentina
| | - L O Manuel
- Instituto de Física Rosario (CONICET) and Universidad Nacional de Rosario, Bv. 27 de Febrero 210 bis, 2000, Rosario, Argentina
| | - A A Aligia
- Instituto de Nanociencia y Nanotecnología CNEA-CONICET, Centro Atómico Bariloche and Instituto Balseiro, 8400, Bariloche, Argentina
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30
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Kurzmann A, Kleeorin Y, Tong C, Garreis R, Knothe A, Eich M, Mittag C, Gold C, de Vries FK, Watanabe K, Taniguchi T, Fal'ko V, Meir Y, Ihn T, Ensslin K. Kondo effect and spin-orbit coupling in graphene quantum dots. Nat Commun 2021; 12:6004. [PMID: 34650056 PMCID: PMC8516925 DOI: 10.1038/s41467-021-26149-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 09/17/2021] [Indexed: 11/30/2022] Open
Abstract
The Kondo effect is a cornerstone in the study of strongly correlated fermions. The coherent exchange coupling of conduction electrons to local magnetic moments gives rise to a Kondo cloud that screens the impurity spin. Here we report on the interplay between spin-orbit interaction and the Kondo effect, that can lead to a underscreened Kondo effects in quantum dots in bilayer graphene. More generally, we introduce a different experimental platform for studying Kondo physics. In contrast to carbon nanotubes, where nanotube chirality determines spin-orbit coupling breaking the SU(4) symmetry of the electronic states relevant for the Kondo effect, we study a planar carbon material where a small spin-orbit coupling of nominally flat graphene is enhanced by zero-point out-of-plane phonons. The resulting two-electron triplet ground state in bilayer graphene dots provides a route to exploring the Kondo effect with a small spin-orbit interaction.
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Affiliation(s)
- Annika Kurzmann
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland.
| | - Yaakov Kleeorin
- Center for the Physics of Evolving Systems, Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Chuyao Tong
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland
| | - Rebekka Garreis
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland
| | - Angelika Knothe
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Marius Eich
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland
| | - Christopher Mittag
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland
| | - Carolin Gold
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland
| | | | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - Vladimir Fal'ko
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Yigal Meir
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Thomas Ihn
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland
- Quantum Center, ETH Zurich, Zurich, 8093, Switzerland
| | - Klaus Ensslin
- Solid State Physics Laboratory, ETH Zürich, Zürich, CH-8093, Switzerland
- Quantum Center, ETH Zurich, Zurich, 8093, Switzerland
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31
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Female directors on corporate boards and their impact on corporate social responsibility (CSR): evidence from China. MANAGEMENT RESEARCH REVIEW 2021. [DOI: 10.1108/mrr-09-2020-0560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose
This study aims to examine the determinants of the female representations on Chinese listed firm’s boards. This study also investigates the effect of gender diversity on corporate social responsibility activities.
Design/methodology/approach
The Tobit regression model is used because the data is censored and using ordinary least square regression can give spurious results. For robust check, the authors also used Heckman’s (1979) two-stage self-selection model to remove the sample self-selection bias.
Findings
The authors find that the female representations on the corporate board are positively associated with firm age, firm performance, corporate governance, family ownership, institutional ownership and managerial ownership while negatively related to firm size and state ownership. This study also incorporates predictors of the critical mass of women on the Chinese listed firm’s board. The study also tests the female-led hypothesis and concludes that the female representation increases in firms with female chief executive officer (CEO) or female chairpersons. The Chinese listed firms with gender-diverse board are socially responsible.
Research limitations/implications
The importance of diversity in corporate boards has been demonstrated in light of the agency theory and the resource dependence framework. The results contribute to the previous literature by documenting the determinants of female representations on board, robust by alternative measures of gender diversity, firm size, corporate governance and estimation techniques.
Practical implications
The economic significance of gender diversity stirred the firms to increase female representation. The policymakers can understand the reasons for female underrepresentation in Chinese boards and can reform the regulation to enhance governance quality, non-state ownership and risk aversion among the listed firms.
Originality/value
This study contributes to the literature by providing empirical evidence on the key predictor of the world’s largest emerging economy, specifically the study focuses on the firm specific determinants, different governance attributes, ownership structure and firm risk measures. This study also seeks to answer if the presence of a female in the Chairperson or CEO position encourages the firms to hire more female directors or not?
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32
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Žonda M, Stetsovych O, Korytár R, Ternes M, Temirov R, Raccanelli A, Tautz FS, Jelínek P, Novotný T, Švec M. Resolving Ambiguity of the Kondo Temperature Determination in Mechanically Tunable Single-Molecule Kondo Systems. J Phys Chem Lett 2021; 12:6320-6325. [PMID: 34228474 DOI: 10.1021/acs.jpclett.1c01544] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Determination of the molecular Kondo temperature (TK) poses a challenge in most cases when the experimental temperature cannot be tuned to a sufficient extent. We show how this ambiguity can be resolved if additional control parameters are present, such as magnetic field and mechanical gating. We record the evolution of the differential conductance by lifting an individual molecule from the metal surface with the tip of a scanning tunneling microscope. By fitting the measured conductance spectra with the single impurity Anderson model we are able to demonstrate that the lifting tunes the junction continuously from the strongly correlated Kondo-singlet to the free spin-1/2 ground state. In the crossover regime, where TK is similar to the temperature of experiment, the fitting yields ambiguous estimates of TK varying by an order of magnitude. We show that analysis of the conductance measured in two distinct external magnetic fields can be used to resolve this problem.
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Affiliation(s)
- Martin Žonda
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2, Czech Republic
- Institute of Physics, Albert Ludwig University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Oleksandr Stetsovych
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, CZ-162 00 Praha 6, Czech Republic
| | - Richard Korytár
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2, Czech Republic
| | - Markus Ternes
- Institute of Physics II B, RWTH Aachen University, 52074 Aachen, Germany
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich Germany
| | - Ruslan Temirov
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich Germany
- Faculty of Mathematics and Natural Sciences, Institute of Physics II, University of Cologne, 50937 Cologne, Germany
| | - Andrea Raccanelli
- Peter Grünberg Institut (Cryo-Lab), Forschungszentrum Jülich, JülichGermany
| | - F Stefan Tautz
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich Germany
- Fundamentals of Future Information Technology, Jülich Aachen Research Alliance (JARA), Jülich, Germany
- Institute of Physics IV A, RWTH Aachen University, Aachen, Germany
| | - Pavel Jelínek
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, CZ-162 00 Praha 6, Czech Republic
- RCPTM, Palacky University, Šlechtitelu 27, 783 71 Olomouc, Czech Republic
| | - Tomáš Novotný
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2, Czech Republic
| | - Martin Švec
- Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, CZ-162 00 Praha 6, Czech Republic
- RCPTM, Palacky University, Šlechtitelu 27, 783 71 Olomouc, Czech Republic
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33
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O'Driscoll LJ, Bryce MR. A review of oligo(arylene ethynylene) derivatives in molecular junctions. NANOSCALE 2021; 13:10668-10711. [PMID: 34110337 DOI: 10.1039/d1nr02023d] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Oligo(arylene ethynylene) (OAE) derivatives are the "workhorse" molecules of molecular electronics. Their ease of synthesis and flexibility of functionalisation mean that a diverse array of OAE molecular wires have been designed, synthesised and studied theoretically and experimentally in molecular junctions using both single-molecule and ensemble methods. This review summarises the breadth of molecular designs that have been investigated with emphasis on structure-property relationships with respect to the electronic conductance of OAEs. The factors considered include molecular length, connectivity, conjugation, (anti)aromaticity, heteroatom effects and quantum interference (QI). Growing interest in the thermoelectric properties of OAE derivatives, which are expected to be at the forefront of research into organic thermoelectric devices, is also explored.
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Affiliation(s)
- Luke J O'Driscoll
- Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham, UKDH1 3LE.
| | - Martin R Bryce
- Department of Chemistry, Durham University, Lower Mountjoy, Stockton Road, Durham, UKDH1 3LE.
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34
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Cheng P, Kong L, Zhang T, Liu H, Fu H, Chen L, Wu K, Chen X, Meng S, Xue QK. In-Situ Manipulation of the Magnetic Anisotropy of Single Mn Atom via Molecular Ligands. NANO LETTERS 2021; 21:3566-3572. [PMID: 33830782 DOI: 10.1021/acs.nanolett.1c00545] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Magnetic anisotropy is essential for permanent magnets to maintain their magnetization along specific directions. Understanding and controlling the magnetic anisotropy on a single-molecule scale are challenging but of fundamental importance for the future's spintronic technology. Here, by using scanning tunneling microscopy (STM), we demonstrated the ability to control the magnetic anisotropy by tuning the ligand field at the single-molecule level. We constructed a molecular magnetic complex with a single Mn atom and an organic molecule (4,4'-biphenyldicarbonitrile) as a ligand via atomic manipulation. Inelastic tunneling spectra (IETS) show that the Mn complex has much larger axial magnetic anisotropy than individual Mn atoms, and the anisotropy energy can be tuned by the coupling strength of the ligand. With density functional theory calculations, we revealed that the enhanced magnetic anisotropy of Mn arising from the carbonitrile ligand provides a prototype for the engineering of the magnetism of quantum devices.
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Affiliation(s)
- Peng Cheng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Longjuan Kong
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
| | - Tong Zhang
- State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200438, China
- Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Hang Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
| | - Huixia Fu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
| | - Lan Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kehui Wu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
- School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xi Chen
- Department of Physics, Tsinghua University, Beijing 100084, China
| | - Sheng Meng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
| | - Qi-Kun Xue
- Department of Physics, Tsinghua University, Beijing 100084, China
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35
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Bahlke MP, Schneeberger M, Herrmann C. Local decomposition of hybridization functions: Chemical insight into correlated molecular adsorbates. J Chem Phys 2021; 154:144108. [PMID: 33858153 DOI: 10.1063/5.0045640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hybridization functions are an established tool for investigating the coupling between a correlated subsystem (often a single transition metal atom) and its uncorrelated environment (the substrate and any ligands present). The hybridization function can provide valuable insight into why and how strong correlation features such as the Kondo effect can be chemically controlled in certain molecular adsorbates. To deepen this insight, we introduce a local decomposition of the hybridization function, based on a truncated cluster approach, enabling us to study individual effects on this function coming from specific parts of the systems (e.g., the surface, ligands, or parts of larger ligands). It is shown that a truncated-cluster approach can reproduce the Co 3d and Mn 3d hybridization functions from periodic boundary conditions in Co(CO)4/Cu(001) and MnPc/Ag(001) qualitatively well. By locally decomposing the hybridization functions, it is demonstrated at which energies the transition metal atoms are mainly hybridized with the substrate or with the ligand. For the Kondo-active 3dx2-y2 orbital in Co(CO)4/Cu(001), the hybridization function at the Fermi energy is substrate-dominated, so we can assign its enhancement compared with ligand-free Co to an indirect effect of ligand-substrate interactions. In MnPc/Ag(001), the same is true for the Kondo-active orbital, but for two other orbitals, there are both direct and indirect effects of the ligand, together resulting in such strong screening that their potential Kondo activity is suppressed. A local decomposition of hybridization functions could also be useful in other areas, such as analyzing the electrode self-energies in molecular junctions.
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Affiliation(s)
- Marc Philipp Bahlke
- Department of Chemistry, University of Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Michaela Schneeberger
- Department of Chemistry, University of Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Carmen Herrmann
- Department of Chemistry, University of Hamburg, Harbor Bldg. 610, Luruper Chaussee 149, 22761 Hamburg, Germany
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36
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Mahmud T, Sifa SF, Islam NN, Rafsan MA, Kamal ASMM, Hossain MS, Rahman MZ, Chakraborty TR. Drought dynamics of Northwestern Teesta Floodplain of Bangladesh: a remote sensing approach to ascertain the cause and effect. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:218. [PMID: 33758982 DOI: 10.1007/s10661-021-09005-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Drought is an affliction for a region that primarily depends on agriculture as economic activity. Commonly monitoring and characterizing of drought is performed by only analyzing the meteorological aspect, assuming precipitation as the primary source of water. However, in riverine Bangladesh, this can lead to an erroneous conclusion, as there is a multitude of available water sources. Consequently, in this study, vegetation condition (Standard Vegetation Index), soil moisture (Soil Moisture Index), and precipitation (Standard Precipitation Index) are separately investigated from 2003 to 2019, in the Northwestern Teesta floodplain. Subsequently, statistical regression analysis is performed to determine the relationships between different aspects of drought. In addition, information obtained from field visits and expert opinions has also been assimilated. Analysis of vegetation and soil moisture condition presents a progressively improving scenario. However, SPI shows an incessant decline in meteorological drought conditions, especially after 2007. Evidently, regression analysis does not provide any indication of an interrelationship between the studied agricultural and meteorological parameters. Presumably, this absence is instigated because the study area is highly irrigated as the groundwater table is suitably near the surface and the existence of nearby Teesta river allows for the utilization of surface water. Moreover, the cropping pattern is shifting toward crops that require much less water and to places where soil moisture is scarce. Thus, this study addresses the gap in knowledge regarding the nature of agricultural drought and the dynamics of different aspects of drought which will be invaluable for the water management and agricultural policy in the study area as well as other regions with a similar backdrop.
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Affiliation(s)
- Tonoy Mahmud
- Department of Disaster Science and Management, University of Dhaka, Dhaka, Bangladesh
| | - Shamima Ferdousi Sifa
- Department of Disaster Science and Management, University of Dhaka, Dhaka, Bangladesh
| | - Nafisa Nuari Islam
- Department of Disaster Science and Management, University of Dhaka, Dhaka, Bangladesh
| | - Md Asif Rafsan
- Department of Disaster Science and Management, University of Dhaka, Dhaka, Bangladesh
| | - A S M Maksud Kamal
- Department of Disaster Science and Management, University of Dhaka, Dhaka, Bangladesh
| | - Md Shakhawat Hossain
- Department of Disaster Science and Management, University of Dhaka, Dhaka, Bangladesh.
| | - Md Zillur Rahman
- Department of Disaster Science and Management, University of Dhaka, Dhaka, Bangladesh
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37
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Nan N, Li W, Wang PC, Hu YJ, Tan GL, Xiong YC. Kondo effect and RKKY interaction assisted by magnetic anisotropy in a frustrated magnetic molecular device at zero and finite temperature. Phys Chem Chem Phys 2021; 23:5878-5887. [PMID: 33659975 DOI: 10.1039/d0cp05915c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Molecular magnetic compounds, which combine the advantages of nanoscale behaviors with the properties of bulk magnetic materials, are particularly attractive in the fields of high-density information storage and quantum computing. Before molecular electronic devices can be fabricated, a crucial task is the measurement and understanding of the transport behaviors. Herein, we consider a magnetic molecular trimer sandwiched between two metal electrodes, and, with the aid of the sophisticated full density matrix numerical renormalization group (FDM-NRG) technique, we study the effect of magnetic anisotropy on the charge transport properties, illustrated by the local density of states (LDOS, which is proportional to the differential conductance), the Kondo effect, and the temperature and inter-monomer hopping robustness. Three kinds of energy peaks are clarified in the LDOS: the Coulomb, the Kondo and the Ruderman-Kittel-Kasuya-Yosida (RKKY) peaks. The local magnetic moment and entropy go through four different regimes as the temperature decreases. The Kondo temperature TK could be described by a generalized Haldane's formula, revealing in detail the process where the local moment is partially screened by the itinerant electrons. A relationship between the width of the Kondo resonant peak WK and TK is built, ensuring the extraction of TK from WK in an efficient way. As the inter-monomer hopping integral varies, the ground state of the trimer changes from a spin quadruplet to a magnetically frustrated phase, then to an orbital spin singlet through two first order quantum phase transitions. In the first two phases, the Kondo peak in the transmission coefficient reaches its unitary limit, while in the orbital spin singlet, it is totally suppressed. We demonstrate that magnetic anisotropy may also induce the Kondo effect, even without Coulomb repulsion, hence it is replaceable in the many-body behaviours at low temperature.
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Affiliation(s)
- Nan Nan
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, People's Republic of China. and School of Science, and Advanced Functional Material and Photoelectric Technology Research Institution, Hubei University of Automotive Technology, Shiyan, 442002, People's Republic of China.
| | - Wei Li
- School of Science, and Advanced Functional Material and Photoelectric Technology Research Institution, Hubei University of Automotive Technology, Shiyan, 442002, People's Republic of China.
| | - Peng-Chao Wang
- School of Science, and Advanced Functional Material and Photoelectric Technology Research Institution, Hubei University of Automotive Technology, Shiyan, 442002, People's Republic of China.
| | - Yong-Jin Hu
- School of Science, and Advanced Functional Material and Photoelectric Technology Research Institution, Hubei University of Automotive Technology, Shiyan, 442002, People's Republic of China.
| | - Guo-Long Tan
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, People's Republic of China.
| | - Yong-Chen Xiong
- School of Science, and Advanced Functional Material and Photoelectric Technology Research Institution, Hubei University of Automotive Technology, Shiyan, 442002, People's Republic of China.
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38
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Guo X, Zhu Q, Zhou L, Yu W, Lu W, Liang W. Evolution and universality of two-stage Kondo effect in single manganese phthalocyanine molecule transistors. Nat Commun 2021; 12:1566. [PMID: 33692347 PMCID: PMC7946881 DOI: 10.1038/s41467-021-21492-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 01/26/2021] [Indexed: 11/19/2022] Open
Abstract
The Kondo effect offers an important paradigm to understand strongly correlated many-body physics. Although under intensive study, some of the important properties of the Kondo effect, in systems where both itinerant coupling and localized coupling play significant roles, are still elusive. Here we report the evolution and universality of the two-stage Kondo effect, the simplest form where both couplings are important using single molecule transistor devices incorporating Manganese phthalocyanine molecules. The Kondo temperature T* of the two-stage Kondo effect evolves linearly against effective interaction of involved two spins. Observed Kondo resonance shows universal quadratic dependence with all adjustable parameters: temperature, magnetic field and biased voltages. The difference in nonequilibrium conductance of two-stage Kondo effect to spin 1/2 Kondo effect is also identified. Messages learned in this study fill in directive experimental evidence of the evolution of two-stage Kondo resonance near a quantum phase transition point, and help in understanding sophisticated molecular electron spectroscopy in a strong correlation regime. The Kondo effect can serve as a powerful paradigm to understand strongly correlated many-body processes in physics. Here, Guo et al. utilize single molecule transistor devices as a testbed to study multi-level Kondo correlation and show electrical gate evolution and the universality of the two-stage Kondo effect.
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Affiliation(s)
- Xiao Guo
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China.,Beijing National center for Condensed Matter Physics, Beijing Key Laboratory for Nanomaterials and Nanodevices, Institute of Physics, Chinese Academy of Sciences, Beijing, P.R. China.,CAS Center of Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Qiuhao Zhu
- Beijing National center for Condensed Matter Physics, Beijing Key Laboratory for Nanomaterials and Nanodevices, Institute of Physics, Chinese Academy of Sciences, Beijing, P.R. China.,CAS Center of Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Liyan Zhou
- Beijing National center for Condensed Matter Physics, Beijing Key Laboratory for Nanomaterials and Nanodevices, Institute of Physics, Chinese Academy of Sciences, Beijing, P.R. China.,CAS Center of Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Wei Yu
- Beijing National center for Condensed Matter Physics, Beijing Key Laboratory for Nanomaterials and Nanodevices, Institute of Physics, Chinese Academy of Sciences, Beijing, P.R. China.,CAS Center of Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Wengang Lu
- Beijing National center for Condensed Matter Physics, Beijing Key Laboratory for Nanomaterials and Nanodevices, Institute of Physics, Chinese Academy of Sciences, Beijing, P.R. China.,CAS Center of Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Wenjie Liang
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China. .,Beijing National center for Condensed Matter Physics, Beijing Key Laboratory for Nanomaterials and Nanodevices, Institute of Physics, Chinese Academy of Sciences, Beijing, P.R. China. .,CAS Center of Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, P.R. China.
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39
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Kim Y. Photoswitching Molecular Junctions: Platforms and Electrical Properties. Chemphyschem 2020; 21:2368-2383. [PMID: 32777151 DOI: 10.1002/cphc.202000564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/07/2020] [Indexed: 11/10/2022]
Abstract
Remarkable advances in technology have enabled the manipulation of individual molecules and the creation of molecular electronic devices utilizing single and ensemble molecules. Maturing the field of molecular electronics has led to the development of functional molecular devices, especially photoswitching or photochromic molecular junctions, which switch electronic properties under external light irradiation. This review introduces and summarizes the platforms for investigating the charge transport in single and ensemble photoswitching molecular junctions as well as the electronic properties of diverse photoswitching molecules such as diarylethene, azobenzene, dihydropyrene, and spiropyran. Furthermore, the article discusses the remaining challenges and the direction for moving forward in this area for future photoswitching molecular devices.
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Affiliation(s)
- Youngsang Kim
- Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA.,Current address, 7644 Ambrose way, California, 95831, USA
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40
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Rabelo R, Toma L, Moliner N, Julve M, Lloret F, Pasán J, Ruiz-Pérez C, Ruiz-García R, Cano J. Electroswitching of the single-molecule magnet behaviour in an octahedral spin crossover cobalt(ii) complex with a redox-active pyridinediimine ligand. Chem Commun (Camb) 2020; 56:12242-12245. [PMID: 32926022 DOI: 10.1039/d0cc03357j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thermal-assisted spin crossover and field-induced slow magnetic relaxation coexist in the solid state for the mononuclear cobalt(ii) complex with the non-innocent 2,6-bis(N-4-methoxyphenylformimidoyl)pyridine ligand. One-electron oxidation of the paramagnetic low-spin CoII ion (SCo = 1/2) to the diamagnetic low-spin CoIII ion (SCo = 0) leads to the electroswitching of the slow magnetic relaxation in acetonitrile solution.
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Affiliation(s)
- Renato Rabelo
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
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41
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Siriwardane EMD, Karki P, Lee Loh Y, Çakır D. Engineering magnetic anisotropy and exchange couplings in double transition metal MXenes via surface defects. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 33:035801. [PMID: 33107444 DOI: 10.1088/1361-648x/abba8e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/22/2020] [Indexed: 06/11/2023]
Abstract
Two-dimensional (2D) materials have been experimentally proven to manifest almost all types of material properties observed in bulk materials. However, 2D magnetism was elusive until recently. In this work, we used an approach that synergistically uses density functional theory, and Monte Carlo methods to investigate the magnetic and electronic properties of magnetic double transition metal MXene alloys (Hf2MnC2O2and Hf2VC2O2) by exploiting realistic surface terminations via creating surface defects including oxygen vacancies and H adatoms. We found that introducing surface oxygen vacancies or hydrogen adatoms is able to modify the electronic structures, magnetic anisotropies, and exchange couplings. Depending on the defect concentration, a ferromagnetic half-metallic state can be realized for both Hf2VC2O2and Hf2MnC2O2. Bare Hf2VC2O2exhibits easy-axis anisotropy, whereas bare Hf2MnC2O2exhibits easy-plane anisotropy; however, defects can change the latter to easy-axis anisotropy, which is preferable for spintronics applications. The considered defects were found to modify the magnetic anisotropy by as much as 300%. Defects also produce an inhomogeneous pattern of exchange couplings, which can further enhance the Curie temperature. In particular, Hf2MnC2O2H0.22was predicted to have a Curie temperature of about 171 K due to a combination of easy-axis anisotropy and a connected network of enhanced exchange couplings. Our calculations suggest a route toward engineering exchange couplings and magnetic anisotropy to improve magnetic properties.
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Affiliation(s)
- Edirisuriya M D Siriwardane
- Department of Physics and Astrophysics, University of North Dakota, Grand Forks, ND 58202, United States of America
| | - Pragalv Karki
- Department of Physics and Astrophysics, University of North Dakota, Grand Forks, ND 58202, United States of America
| | - Yen Lee Loh
- Department of Physics and Astrophysics, University of North Dakota, Grand Forks, ND 58202, United States of America
| | - Deniz Çakır
- Department of Physics and Astrophysics, University of North Dakota, Grand Forks, ND 58202, United States of America
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42
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Su X, Li C, Du Q, Tao K, Wang S, Yu P. Atomically Precise Synthesis and Characterization of Heptauthrene with Triplet Ground State. NANO LETTERS 2020; 20:6859-6864. [PMID: 32787160 DOI: 10.1021/acs.nanolett.0c02939] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
By virtue of multitunable spin structures upon designing the π-electron topologies, phenalenyl-based nanographenes are of substantial interest in fundamental science and for potential applications in spintronics. Heptauthrene, as one of the well-known phenalenyl diradicals, is composed of one benzene-fused bisphenalenyls in mirror symmetry and expected to have a triplet ground state. However, the synthesis of unsubstituted heptauthrene remains very challenging due to the high reactivity of triplet diradicals. Here, we report a combined in-solution and on-surface synthesis of unsubstituted heptauthrene, whose chemical structure is characterized through bond-resolved atomic force microscopy. Combined with mean-field Hubbard model calculations, its triplet ground state is unambiguously confirmed by the underscreened Kondo resonance in response to the magnetic field, as well as the engineered spin-state switching upon extra hydrogen atom addition and dissociation on the radical site. Our results provide access to phenalenyl-based nanographenes with high-spin ground state, potentially useful in constructing high-spin networks.
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Affiliation(s)
- Xuelei Su
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Can Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qingyang Du
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Kun Tao
- Key Lab for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, 730000 LanZhou, China
| | - Shiyong Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ping Yu
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
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43
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Strategic Orientation and Effects of E-Administration: Findings from the Miles and Snow Framework. ADMINISTRATIVE SCIENCES 2020. [DOI: 10.3390/admsci10020035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Much has been written about the strategic orientation of public administration organizations (prospecting, defending, reacting, and analyzing) and their consequences for organizational effects, but little is dedicated to e-administration. Is the provision of services using IT affecting the adoption of strategic orientation and its effects? The paper is dealing with e-administration issues, specifically in terms of the impact of the Miles and Snow strategic orientation on e-administration effects. To measure e-administration effects, the author’s personal tool using the Common Assessment Framework (CAF) criterion has been proposed. The data collection was conducted using the Computer-Assisted Web Interview (CAWI) method, in the period from November 2017 to January 2018. Two hundred and twenty-six Polish organizations took part in the study. The objective of this study, i.e., assessing the impact of strategic orientation and e-administration effects, was achieved by using the Ordinary Least Squares (OLS) method. It is indicated that the Defender orientation is positively associated with the effects of e-administration.
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44
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Li J, Sanz S, Castro-Esteban J, Vilas-Varela M, Friedrich N, Frederiksen T, Peña D, Pascual JI. Uncovering the Triplet Ground State of Triangular Graphene Nanoflakes Engineered with Atomic Precision on a Metal Surface. PHYSICAL REVIEW LETTERS 2020; 124:177201. [PMID: 32412280 DOI: 10.1103/physrevlett.124.177201] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/17/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
Graphene can develop large magnetic moments in custom-crafted open-shell nanostructures such as triangulene, a triangular piece of graphene with zigzag edges. Current methods of engineering graphene nanosystems on surfaces succeeded in producing atomically precise open-shell structures, but demonstration of their net spin remains elusive to date. Here, we fabricate triangulenelike graphene systems and demonstrate that they possess a spin S=1 ground state. Scanning tunneling spectroscopy identifies the fingerprint of an underscreened S=1 Kondo state on these flakes at low temperatures, signaling the dominant ferromagnetic interactions between two spins. Combined with simulations based on the meanfield Hubbard model, we show that this S=1 π paramagnetism is robust and can be turned into an S=1/2 state by additional H atoms attached to the radical sites. Our results demonstrate that π paramagnetism of high-spin graphene flakes can survive on surfaces, opening the door to study the quantum behavior of interacting π spins in graphene systems.
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Affiliation(s)
- Jingcheng Li
- CIC Nanogune BRTA, 20018 Donostia-San Sebastián, Spain
| | - Sofia Sanz
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
| | - Jesus Castro-Esteban
- 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
| | - Manuel Vilas-Varela
- 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
| | | | - Thomas Frederiksen
- Donostia International Physics Center (DIPC), 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
| | - Jose Ignacio Pascual
- CIC Nanogune BRTA, 20018 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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45
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Perrin ML, Eelkema R, Thijssen J, Grozema FC, van der Zant HSJ. Single-molecule functionality in electronic components based on orbital resonances. Phys Chem Chem Phys 2020; 22:12849-12866. [DOI: 10.1039/d0cp01448f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A gateable single-molecule diode and resonant tunneling diode are realized using molecular orbital engineering in multi-site molecules.
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Affiliation(s)
- Mickael L. Perrin
- Kavli Institute of Nanoscience
- Delft University of Technology
- 2628 CJ Delft
- The Netherlands
- Swiss Federal Laboratories for Materials Science and Technology
| | - Rienk Eelkema
- Department of Chemical Engineering
- Delft University of Technology
- 2629 HZ Delft
- The Netherlands
| | - Jos Thijssen
- Kavli Institute of Nanoscience
- Delft University of Technology
- 2628 CJ Delft
- The Netherlands
| | - Ferdinand C. Grozema
- Department of Chemical Engineering
- Delft University of Technology
- 2629 HZ Delft
- The Netherlands
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46
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Wang Y, Li X, Yang J. Spin-flip excitations induced by dehydrogenation in a magnetic single-molecule junction. J Chem Phys 2019; 151:224704. [DOI: 10.1063/1.5129288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Yu Wang
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Xiaoguang Li
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Jinlong Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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47
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Roura-Bas P, Güller F, Tosi L, Aligia AA. Destructive quantum interference in transport through molecules with electron-electron and electron-vibration interactions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:465602. [PMID: 31357183 DOI: 10.1088/1361-648x/ab3684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We study the transport through a molecular junction exhibiting interference effects. We show that these effects can still be observed in the presence of molecular vibrations if Coulomb repulsion is taken into account. In the Kondo regime, the conductance of the junction can be changed by several orders of magnitude by tuning the levels of the molecule, or displacing a contact between two atoms, from nearly perfect destructive interference to values of the order of 2e 2/h expected in Kondo systems. We also show that this large conductance change is robust for reasonable temperatures and voltages for symmetric and asymmetric tunnel couplings between the source-drain electrodes and the molecular orbitals. This is relevant for the development of quantum interference effect transistors based on molecular junctions.
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Affiliation(s)
- P Roura-Bas
- Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica, CONICET, 8400 Bariloche, Argentina
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48
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Schmitz S, Qiu X, Glöß M, van Leusen J, Izarova NV, Nadeem MA, Griebel J, Chiechi RC, Kögerler P, Monakhov KY. Conductive Self-Assembled Monolayers of Paramagnetic {Co II Co 4 III } and { Co 4 II Co 2 III } Coordination Clusters on Gold Surfaces. Front Chem 2019; 7:681. [PMID: 31750287 PMCID: PMC6848059 DOI: 10.3389/fchem.2019.00681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/01/2019] [Indexed: 11/13/2022] Open
Abstract
Two polynuclear cobalt(II,III) complexes, [Co5(N3)4(N-n-bda)4(bza·SMe)2] (1) and [Co6(N3)4(N-n-bda)2(bza·SMe)5(MeOH)4]Cl (2), where Hbza·SMe = 4-(methylthio)benzoic acid and N-n-H2bda = N-n-butyldiethanolamine, were synthesized and fully characterized by various techniques. Compound 1 exhibits an unusual, approximately C 2-symmetric {CoIICo 4 III } core of two isosceles Co3 triangles with perpendicularly oriented planes, sharing a central, high-spin CoII ion residing in a distorted tetrahedral coordination environment. This central CoII ion is connected to four outer, octahedrally coordinated low-spin CoIII ions via oxo bridges. Compound 2 comprises a semi-circular {Co 4 II Co 2 III } motif of four non-interacting high-spin CoII and two low-spin CoIII centers in octahedral coordination environments. Self-assembled monolayers (SAMs) of 1 and 2 were physisorbed on template-stripped gold surfaces contacted by an eutectic gallium-indium (EGaIn) tip. The acquired current density-voltage (I-V) data revealed that the cobalt-based SAMs are more electrically robust than those of the previously reported dinuclear {CuIILnIII} complexes with Ln = Gd, Tb, Dy, or Y (Schmitz et al., 2018a). In addition, between 170 and 220°C, the neutral, mixed-valence compound 1 undergoes a redox modification, yielding a {Co5}-based coordination cluster (1-A) with five non-interacting, high-spin octahedral CoII centers as indicated by SQUID magnetometry analysis in combination with X-ray photoelectron spectroscopy and infrared spectroscopy. Solvothermal treatment of 1 results in a high-nuclearity coordination cluster, [Co10(N3)2(N-n-bda)6(bza·SMe)6] (3), containing 10 virtually non-interacting high-spin CoII centers.
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Affiliation(s)
- Sebastian Schmitz
- Institut für Anorganische Chemie, RWTH Aachen University, Aachen, Germany
- Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany
| | - Xinkai Qiu
- Stratingh Institute for Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Maria Glöß
- Institut für Anorganische Chemie, RWTH Aachen University, Aachen, Germany
- Jülich-Aachen Research Alliance (JARA-FIT), Peter Grünberg Institute, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Jan van Leusen
- Institut für Anorganische Chemie, RWTH Aachen University, Aachen, Germany
| | - Natalya V. Izarova
- Jülich-Aachen Research Alliance (JARA-FIT), Peter Grünberg Institute, Forschungszentrum Jülich GmbH, Jülich, Germany
| | | | - Jan Griebel
- Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany
| | - Ryan C. Chiechi
- Stratingh Institute for Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
| | - Paul Kögerler
- Institut für Anorganische Chemie, RWTH Aachen University, Aachen, Germany
- Jülich-Aachen Research Alliance (JARA-FIT), Peter Grünberg Institute, Forschungszentrum Jülich GmbH, Jülich, Germany
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49
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Xie L, Lin H, Zhang C, Li J, Merino-Díez N, Friedrich N, Bouju X, Li Y, Pascual JI, Xu W. Switching the Spin on a Ni Trimer within a Metal-Organic Motif by Controlling the On-Top Bromine Atom. ACS NANO 2019; 13:9936-9943. [PMID: 31381315 DOI: 10.1021/acsnano.9b04715] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Controlling the spin of metal atoms embedded in molecular systems is a key step toward the realization of molecular electronics and spintronics. Many efforts have been devoted to explore the influencing factors dictating the survival or quenching of a magnetic moment in a metal-organic molecule, and among others, the spin control by axial ligand attachments is the most promising. Herein, from the interplay of high-resolution scanning tunneling microscopy imaging/manipulation and scanning tunneling spectroscopy measurements together with density functional theory calculations, we successfully demonstrate that a Ni trimer within a metal-organic motif acquires a net spin promoted by the adsorption of an on-top Br atom. The spin localization in the trimetal centers bonded to Br was monitored via the Kondo effect. The removal of the Br ligand resulted in the switch from a Kondo ON to a Kondo OFF state. The magnetic state induced by the Br ligand is theoretically attributed to the enhanced Br 4pz and Ni 3dz2 states due to the charge redistribution. The manipulation strategy reported here provides the possibility to explore potential applications of spin-tunable structures in spintronic devices.
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Affiliation(s)
- Lei Xie
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering , Tongji University , Shanghai 201804 , People's Republic of China
| | - Haiping Lin
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , 199 Ren'ai Road , Suzhou 215123 , Jiangsu , People's Republic of China
| | - Chi Zhang
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering , Tongji University , Shanghai 201804 , People's Republic of China
| | - Jingcheng Li
- CIC nanoGUNE , 20018 San Sebastián-Donostia , Spain
| | - Nestor Merino-Díez
- CIC nanoGUNE , 20018 San Sebastián-Donostia , Spain
- Donostia International Physics Center (DIPC) , 20018 San Sebastián-Donostia , Spain
| | | | - Xavier Bouju
- CEMES-CNRS, Université de Toulouse , 31000 Toulouse , France
| | - Youyong Li
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , 199 Ren'ai Road , Suzhou 215123 , Jiangsu , People's Republic of China
| | - Jose Ignacio Pascual
- CIC nanoGUNE , 20018 San Sebastián-Donostia , Spain
- Ikerbasque, Basque Foundation for Science , 48013 Bilbao , Spain
| | - Wei Xu
- Interdisciplinary Materials Research Center, College of Materials Science and Engineering , Tongji University , Shanghai 201804 , People's Republic of China
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50
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Czap G, Wagner PJ, Li J, Xue F, Yao J, Wu R, Ho W. Detection of Spin-Vibration States in Single Magnetic Molecules. PHYSICAL REVIEW LETTERS 2019; 123:106803. [PMID: 31573305 DOI: 10.1103/physrevlett.123.106803] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Indexed: 06/10/2023]
Abstract
The spin states of magnetic molecules have advantageous attributes as carriers of quantum information. However, spin-vibration coupling in molecules causes a decay of excited spin states and a loss of spin coherence. Here, we detect excitations of spin-vibration states in single nickelocene molecules on Ag(110) with a scanning tunneling microscope. By transferring a nickelocene to the tip, the joint spin-vibration states with an adsorbed nickelocene were measured. Chemical variations in magnetic molecules offer the opportunity to tune spin-vibration coupling for controlling the spin coherence.
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Affiliation(s)
- Gregory Czap
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - Peter J Wagner
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - Jie Li
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - Feng Xue
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences, Fudan University, Shanghai, China 200433
| | - Jiang Yao
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - R Wu
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences, Fudan University, Shanghai, China 200433
| | - W Ho
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
- Department of Chemistry, University of California, Irvine, California 92697-2025, USA
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