1
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Erpenbeck A, Gull E, Cohen G. Shaping Electronic Flows with Strongly Correlated Physics. NANO LETTERS 2023; 23:10480-10489. [PMID: 37955307 DOI: 10.1021/acs.nanolett.3c03067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Nonequilibrium quantum transport is of central importance in nanotechnology. Its description requires the understanding of strong electronic correlations that couple atomic-scale phenomena to the nanoscale. So far, research in correlated transport has focused predominantly on few-channel transport, precluding the investigation of cross-scale effects. Recent theoretical advances enable the solution of models that capture the interplay between quantum correlations and confinement beyond a few channels. This problem is the focus of this study. We consider an atomic impurity embedded in a metallic nanosheet spanning two leads, showing that transport is significantly altered by tuning only the phase of a single local hopping parameter. Furthermore─depending on this phase─correlations reshape the electronic flow throughout the sheet, either funneling it through the impurity or scattering it away from a much larger region. This demonstrates the potential for quantum correlations to bridge length scales in the design of nanoelectronic devices and sensors.
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Affiliation(s)
- Andre Erpenbeck
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Emanuel Gull
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Guy Cohen
- The Raymond and Beverley Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
- School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel
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2
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Yonemoto R, Ueda R, Otomo A, Noguchi Y. Light-Emitting Electrochemical Cells Based on Nanogap Electrodes. NANO LETTERS 2023; 23:7493-7499. [PMID: 37579029 DOI: 10.1021/acs.nanolett.3c02001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
In a light-emitting electrochemical cell (LEC), electrochemical doping caused by mobile ions facilitates bipolar charge injection and recombination emissions for a high electroluminescence (EL) intensity at low driving voltages. We present the development of a nanogap LEC (i.e., nano-LEC) comprising a light-emitting polymer (F8BT) and an ionic liquid deposited on a gold nanogap electrode. The device demonstrated a high EL intensity at a wavelength of 540 nm corresponding to the emission peak of F8BT and a threshold voltage of ∼2 V at 300 K. Upon application of a constant voltage, the device demonstrated a gradual increase in current intensity followed by light emission. Notably, the delayed components of the current and EL were strongly suppressed at low temperatures (<285 K). The results clearly indicate that the device functions as an LEC and that the nano-LEC is a promising approach to realizing molecular-scale current-induced light sources.
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Affiliation(s)
- Ryo Yonemoto
- Graduate School of Science and Technology, Meiji University, Kawasaki 214-8571, Japan
| | - Rieko Ueda
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Akira Otomo
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Yutaka Noguchi
- Graduate School of Science and Technology, Meiji University, Kawasaki 214-8571, Japan
- School of Science & Technology, Meiji University, Kawasaki 214-8571, Japan
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3
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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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4
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Tyagi P, Brown H, Grizzle A, D'Angelo C, Dahal BR. Molecular coupling competing with defects within insulator of the magnetic tunnel junction-based molecular spintronics devices. Sci Rep 2021; 11:17128. [PMID: 34429460 PMCID: PMC8384883 DOI: 10.1038/s41598-021-96477-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 08/04/2021] [Indexed: 11/24/2022] Open
Abstract
Nearly 70 years old dream of incorporating molecule as the device element is still challenged by competing defects in almost every experimentally tested molecular device approach. This paper focuses on the magnetic tunnel junction (MTJ) based molecular spintronics device (MTJMSD) method. An MTJMSD utilizes a tunnel barrier to ensure a robust and mass-producible physical gap between two ferromagnetic electrodes. MTJMSD approach may benefit from MTJ's industrial practices; however, the MTJMSD approach still needs to overcome additional challenges arising from the inclusion of magnetic molecules in conjunction with competing defects. Molecular device channels are covalently bonded between two ferromagnets across the insulating barrier. An insulating barrier may possess a variety of potential defects arising during the fabrication or operational phase. This paper describes an experimental and theoretical study of molecular coupling between ferromagnets in the presence of the competing coupling via an insulating tunnel barrier. We discuss the experimental observations of hillocks and pinhole-type defects producing inter-layer coupling that compete with molecular device elements. We performed theoretical simulations to encompass a wide range of competition between molecules and defects. Monte Carlo Simulation (MCS) was used for investigating the defect-induced inter-layer coupling on MTJMSD. Our research may help understand and design molecular spintronics devices utilizing various insulating spacers such as aluminum oxide (AlOx) and magnesium oxide (MgO) on a wide range of metal electrodes. This paper intends to provide practical insights for researchers intending to investigate the molecular device properties via the MTJMSD approach and do not have a background in magnetic tunnel junction fabrication.
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Affiliation(s)
- Pawan Tyagi
- Center for Nanotechnology Research and Education, Mechanical Engineering, University of the District of Columbia, Washington, DC, 20008, USA.
| | - Hayden Brown
- Center for Nanotechnology Research and Education, Mechanical Engineering, University of the District of Columbia, Washington, DC, 20008, USA
| | - Andrew Grizzle
- Center for Nanotechnology Research and Education, Mechanical Engineering, University of the District of Columbia, Washington, DC, 20008, USA
| | - Christopher D'Angelo
- Center for Nanotechnology Research and Education, Mechanical Engineering, University of the District of Columbia, Washington, DC, 20008, USA
| | - Bishnu R Dahal
- Center for Nanotechnology Research and Education, Mechanical Engineering, University of the District of Columbia, Washington, DC, 20008, USA
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5
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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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6
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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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7
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Yang Y, Gu C, Li J. Sub-5 nm Metal Nanogaps: Physical Properties, Fabrication Methods, and Device Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1804177. [PMID: 30589217 DOI: 10.1002/smll.201804177] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/29/2018] [Indexed: 05/26/2023]
Abstract
Sub-5 nm metal nanogaps have attracted widespread attention in physics, chemistry, material sciences, and biology due to their physical properties, including great plasmon-enhanced effects in light-matter interactions and charge tunneling, Coulomb blockade, and the Kondo effect under an electrical stimulus. These properties especially meet the needs of many cutting-edge devices, such as sensing, optical, molecular, and electronic devices. However, fabricating sub-5 nm nanogaps is still challenging at the present, and scaled and reliable fabrication, improved addressability, and multifunction integration are desired for further applications in commercial devices. The aim of this work is to provide a comprehensive overview of sub-5 nm nanogaps and to present recent advancements in metal nanogaps, including their physical properties, fabrication methods, and device applications, with the ultimate aim to further inspire scientists and engineers in their research.
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Affiliation(s)
- Yang Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Changzhi Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Junjie Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
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8
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Sawtelle SD, Kobos ZA, Reed MA. Critical temperature in feedback-controlled electromigration of gold nanostructures. NANOTECHNOLOGY 2019; 30:015201. [PMID: 30362467 DOI: 10.1088/1361-6528/aae673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper presents several experiments demonstrating the need for a more nuanced picture of electromigration (EM) than that of a fixed critical junction temperature at which EM onset occurs. Our data suggests that even for a fixed cross-sectional geometry the critical junction temperature for EM, T c , varies with environmental temperature, thermal resistance of adjacent regions, and even the direction of the current flow in asymmetric structures. We have performed feedback-controlled EM on nanowires at environmental temperatures between 75 and 260 K and fit the EM onset points with a constant junction power model. We find that average fit critical power is monotonically increasing with decreasing temperature, but is decidedly nonlinear at lower temperatures. We extract and compare the corresponding T c values using several different thermal models which utilize measured values of nanowire thermal conductivity for our devices: these models all agree on a moderately increasing T c with decreasing environmental temperature. This is tentatively explained by enhanced current-driven annealing on the voltage ramp prior to EM onset which decreases structural scattering, thereby increasing the critical temperature at which wind-force-driven hopping events will achieve a critical atomic flux. We also obtain fit critical power for a series of bowtie structures of identical constriction but varying adjacent thermal resistance (R th ), and estimate that T c in the constriction varies with R th for higher resistance structures. Critical power measurements on a second series of asymmetric bowties further suggests that T c also depends on the alignment of the electron flow with the temperature gradient at the constriction.
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Affiliation(s)
- S D Sawtelle
- Department of Applied Physics, Yale University, New Haven, CT 06520 United States of America
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9
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Zharinov VS, Baumans XDA, Silhanek AV, Janssens E, Van de Vondel J. Controlled electromigration protocol revised. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:043904. [PMID: 29716358 DOI: 10.1063/1.5011953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Electromigration has evolved from an important cause of failure in electronic devices to an appealing method, capable of modifying the material properties and geometry of nanodevices. Although this technique has been successfully used by researchers to investigate low dimensional systems and nanoscale objects, its low controllability remains a serious limitation. This is in part due to the inherent stochastic nature of the process, but also due to the inappropriate identification of the relevant control parameters. In this study, we identify a suitable process variable and propose a novel control algorithm that enhances the controllability and, at the same time, minimizes the intervention of an operator. As a consequence, the algorithm facilitates the application of electromigration to systems that require exceptional control of, for example, the width of a narrow junction. It is demonstrated that the electromigration rate can be stabilized on pre-set values, which eventually defines the final geometry of the electromigrated structures.
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Affiliation(s)
- Vyacheslav S Zharinov
- Laboratory of Solid State Physics and Magnetism, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium
| | - Xavier D A Baumans
- Experimental Physics of Nanostructured Materials, Q-MAT, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
| | - Alejandro V Silhanek
- Experimental Physics of Nanostructured Materials, Q-MAT, CESAM, Université de Liège, B-4000 Sart Tilman, Belgium
| | - Ewald Janssens
- Laboratory of Solid State Physics and Magnetism, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium
| | - Joris Van de Vondel
- Laboratory of Solid State Physics and Magnetism, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium
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10
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Arnold D, Marz M, Schneider S, Hoffmann-Vogel R. Structure and local charging of electromigrated Au nanocontacts. NANOTECHNOLOGY 2017; 28:055206. [PMID: 28032610 DOI: 10.1088/1361-6528/28/5/055206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We study the structure and the electronic properties of Au nanocontacts created by controlled electromigration of thin film devices, a method frequently used to contact molecules. In contrast to electromigration testing, a current is applied in a cyclic fashion and during each cycle the resistance increase of the metal upon heating is used to avoid thermal runaway. In this way, nanometer sized-gaps are obtained. The thin film devices with an optimized structure at the origin of the electromigration process are made by shadow evaporation without contamination by organic materials. Defining rounded edges and a thinner area in the center of the device allow to pre-determine the location where the electromigration takes place. Scanning force microscopy images of the pristine Au film and electromigrated contact show its grainy structure. Through electromigration, a 1.5 μm-wide slit is formed, with extensions only on the anode side that had previously not been observed in narrower structures. It is discussed whether this could be explained by asymmetric heating of both electrodes. New grains are formed in the slit and on the extensions on both, the anode and the cathode side. The smaller structures inside the slit lead to an electrode distance below 150 nm. Kelvin probe force microscopy images show a local work function difference with fluctuations of 70 mV on the metal before electromigration. Between the electrodes, disconnected through electromigration, a work function difference of 3.2 V is observed due to charging. Some of the grains newly formed by electromigration are electrically disconnected from the electrodes.
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Affiliation(s)
- D Arnold
- Physikalisches Institut, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
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11
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Xiang D, Wang X, Jia C, Lee T, Guo X. Molecular-Scale Electronics: From Concept to Function. Chem Rev 2016; 116:4318-440. [DOI: 10.1021/acs.chemrev.5b00680] [Citation(s) in RCA: 816] [Impact Index Per Article: 102.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Dong Xiang
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
- Key
Laboratory of Optical Information Science and Technology, Institute
of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071, China
| | - Xiaolong Wang
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
| | - Chuancheng Jia
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
| | - Takhee Lee
- Department
of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea
| | - Xuefeng Guo
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
- Department
of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
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12
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Cui A, Dong H, Hu W. Nanogap Electrodes towards Solid State Single-Molecule Transistors. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:6115-6141. [PMID: 26450402 DOI: 10.1002/smll.201501283] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/23/2015] [Indexed: 06/05/2023]
Abstract
With the establishment of complementary metal-oxide-semiconductor (CMOS)-based integrated circuit technology, it has become more difficult to follow Moore's law to further downscale the size of electronic components. Devices based on various nanostructures were constructed to continue the trend in the minimization of electronics, and molecular devices are among the most promising candidates. Compared with other candidates, molecular devices show unique superiorities, and intensive studies on molecular devices have been carried out both experimentally and theoretically at the present time. Compared to two-terminal molecular devices, three-terminal devices, namely single-molecule transistors, show unique advantages both in fundamental research and application and are considered to be an essential part of integrated circuits based on molecular devices. However, it is very difficult to construct them using the traditional microfabrication techniques directly, thus new fabrication strategies are developed. This review aims to provide an exclusive way of manufacturing solid state gated nanogap electrodes, the foundation of constructing transistors of single or a few molecules. Such single-molecule transistors have the potential to be used to build integrated circuits.
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Affiliation(s)
- Ajuan Cui
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Huanli Dong
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Wenping Hu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China
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13
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Yoshida K, Shibata K, Hirakawa K. Terahertz Field Enhancement and Photon-Assisted Tunneling in Single-Molecule Transistors. PHYSICAL REVIEW LETTERS 2015; 115:138302. [PMID: 26451585 DOI: 10.1103/physrevlett.115.138302] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Indexed: 06/05/2023]
Abstract
We have investigated the electron transport in single-C_{60}-molecule transistors under the illumination of intense monochromatic terahertz (THz) radiation. By employing an antenna structure with a sub-nm-wide gap, we concentrate THz radiation beyond the diffraction limit and focus it onto a single molecule. Photon-assisted tunneling (PAT) in the single molecule transistors is observed in both the weak-coupling and Kondo regimes. The THz power dependence of the PAT conductance indicates that when the incident THz intensity is a few tens of mW, the THz field induced at the molecule exceeds 100 kV/cm, which is enhanced by a factor of ~10^{5} from the field in the free space.
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Affiliation(s)
- Kenji Yoshida
- Center for Photonics Electronics Convergence, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Kenji Shibata
- Center for Photonics Electronics Convergence, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Kazuhiko Hirakawa
- Center for Photonics Electronics Convergence, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
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14
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Abstract
The use of a gate electrode allows us to gain deeper insight into the electronic structure of molecular junctions. It is widely used for spectroscopy of the molecular levels and its excited states, for changing the charge state of the molecule and investigating higher order processes such as co-tunneling and the Kondo effect. Gate electrodes have been implemented in several types of nanoscale devices such as electromigration junctions, mechanically controllable break junctions, and devices with carbon-based electrodes. Here we review the state-of-the-art in the field of single-molecule transitors. We discuss the experimental challenges and describe the advances made for the different approaches.
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Affiliation(s)
- Mickael L Perrin
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
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15
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Jo HY, Yoo PS, Kim T. Oxygen-Silver Junction Formation for Single Molecule Conductance. JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2015. [DOI: 10.5012/jkcs.2015.59.1.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Sun L, Diaz-Fernandez YA, Gschneidtner TA, Westerlund F, Lara-Avila S, Moth-Poulsen K. Single-molecule electronics: from chemical design to functional devices. Chem Soc Rev 2014; 43:7378-411. [DOI: 10.1039/c4cs00143e] [Citation(s) in RCA: 361] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The use of single molecules in electronics represents the next limit of miniaturisation of electronic devices, which would enable to continue the trend of aggressive downscaling of silicon-based electronic devices.
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Affiliation(s)
- Lanlan Sun
- Department of Chemical and Biological Engineering
- Chalmers University of Technology
- , Sweden
| | - Yuri A. Diaz-Fernandez
- Department of Chemical and Biological Engineering
- Chalmers University of Technology
- , Sweden
| | - Tina A. Gschneidtner
- Department of Chemical and Biological Engineering
- Chalmers University of Technology
- , Sweden
| | - Fredrik Westerlund
- Department of Chemical and Biological Engineering
- Chalmers University of Technology
- , Sweden
| | - Samuel Lara-Avila
- Department of Micro and Nanotechnology
- MC2
- Chalmers University of Technology
- , Sweden
| | - Kasper Moth-Poulsen
- Department of Chemical and Biological Engineering
- Chalmers University of Technology
- , Sweden
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17
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Kuo CT, Su LC, Chen CH. Transitions between Electron Transporting Mechanisms in Molecular Junctions and Transistors. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.201300504] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Rudneva M, Gao B, Prins F, Xu Q, van der Zant HSJ, Zandbergen HW. In situ transmission electron microscopy imaging of electromigration in platinum nanowires. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19 Suppl 5:43-48. [PMID: 23920172 DOI: 10.1017/s1431927613012300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In situ transmission electron microscopy was performed on the electromigration in platinum (Pt) nanowires (14 nm thick, 200 nm wide, and 300 nm long) with and without feedback control. Using the feedback control mode, symmetric electrodes are obtained and the gap usually forms at the center of the Pt nanowire. Without feedback control, asymmetric electrodes are formed, and the gap can occur at any position along the wire. The three-dimensional gap geometries of the electrodes in the Pt nanowire were determined using high-angle annular dark-field scanning transmission electron microscopy; the thickness of the nanowire is reduced from 14 nm to only a few atoms at the edge with a gap of about 5-10 nm.
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Affiliation(s)
- Maria Rudneva
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
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19
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Li D, Gannett PM, Lederman D. An investigation into the feasibility of myoglobin-based single-electron transistors. NANOTECHNOLOGY 2012; 23:395705. [PMID: 22972432 PMCID: PMC4802369 DOI: 10.1088/0957-4484/23/39/395705] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Myoglobin single-electron transistors were investigated using nanometer-gap platinum electrodes fabricated by electromigration at cryogenic temperatures. Apomyoglobin (myoglobin without the heme group) was used as a reference. The results suggest single-electron transport is mediated by resonant tunneling with the electronic and vibrational levels of the heme group in a single protein. They also represent a proof-of-principle that proteins with redox centers across nanometer-gap electrodes can be utilized to fabricate single-electron transistors. The protein orientation and conformation may significantly affect the conductance of these devices. Future improvements in device reproducibility and yield will require control of these factors.
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Affiliation(s)
- Debin Li
- Department of Physics, West Virginia University, Morgantown, WV, 26506-6315, USA
| | - Peter M. Gannett
- Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV, 26506-9500, USA
| | - David Lederman
- Department of Physics, West Virginia University, Morgantown, WV, 26506-6315, USA
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20
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Tsutsui M, Taniguchi M. Single molecule electronics and devices. SENSORS (BASEL, SWITZERLAND) 2012; 12:7259-98. [PMID: 22969345 PMCID: PMC3435974 DOI: 10.3390/s120607259] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 05/15/2012] [Accepted: 05/17/2012] [Indexed: 11/21/2022]
Abstract
The manufacture of integrated circuits with single-molecule building blocks is a goal of molecular electronics. While research in the past has been limited to bulk experiments on self-assembled monolayers, advances in technology have now enabled us to fabricate single-molecule junctions. This has led to significant progress in understanding electron transport in molecular systems at the single-molecule level and the concomitant emergence of new device concepts. Here, we review recent developments in this field. We summarize the methods currently used to form metal-molecule-metal structures and some single-molecule techniques essential for characterizing molecular junctions such as inelastic electron tunnelling spectroscopy. We then highlight several important achievements, including demonstration of single-molecule diodes, transistors, and switches that make use of electrical, photo, and mechanical stimulation to control the electron transport. We also discuss intriguing issues to be addressed further in the future such as heat and thermoelectric transport in an individual molecule.
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Affiliation(s)
- Makusu Tsutsui
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan; E-Mail:
| | - Masateru Taniguchi
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan; E-Mail:
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21
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Motto P, Dimonte A, Rattalino I, Demarchi D, Piccinini G, Civera P. Nanogap structures for molecular nanoelectronics. NANOSCALE RESEARCH LETTERS 2012; 7:113. [PMID: 22321736 PMCID: PMC3292911 DOI: 10.1186/1556-276x-7-113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 02/09/2012] [Indexed: 05/11/2023]
Abstract
This study is focused on the realization of nanodevices for nano and molecular electronics, based on molecular interactions in a metal-molecule-metal (M-M-M) structure. In an M-M-M system, the electronic function is a property of the structure and can be characterized through I/V measurements. The contact between the metals and the molecule was obtained by gold nanogaps (with a dimension of less than 10 nm), produced with the electromigration technique. The nanogap fabrication was controlled by a custom hardware and the related software system. The studies were carried out through experiments and simulations of organic molecules, in particular oligothiophenes.
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Affiliation(s)
- Paolo Motto
- Department of Electronics, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Alice Dimonte
- Italian Institute of Technology, IIT@Polito Center, Corso Trento 21, Turin, Italy
| | - Ismael Rattalino
- Italian Institute of Technology, IIT@Polito Center, Corso Trento 21, Turin, Italy
| | - Danilo Demarchi
- Department of Electronics, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Gianluca Piccinini
- Department of Electronics, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Pierluigi Civera
- Department of Electronics, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
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22
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Lee JT, Chae DH, Yao Z, Sessler JL. High-order tunneling processes in single-porphyrin transistors. Chem Commun (Camb) 2012; 48:4420-2. [DOI: 10.1039/c2cc31371e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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23
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Song H, Reed MA, Lee T. Single molecule electronic devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2011; 23:1583-1608. [PMID: 21290434 DOI: 10.1002/adma.201004291] [Citation(s) in RCA: 256] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Indexed: 05/30/2023]
Abstract
Single molecule electronic devices in which individual molecules are utilized as active electronic components constitute a promising approach for the ultimate miniaturization and integration of electronic devices in nanotechnology through the bottom-up strategy. Thus, the ability to understand, control, and exploit charge transport at the level of single molecules has become a long-standing desire of scientists and engineers from different disciplines for various potential device applications. Indeed, a study on charge transport through single molecules attached to metallic electrodes is a very challenging task, but rapid advances have been made in recent years. This review article focuses on experimental aspects of electronic devices made with single molecules, with a primary focus on the characterization and manipulation of charge transport in this regime.
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Affiliation(s)
- Hyunwook Song
- Department of Materials Science and Engineering, Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
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24
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25
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Gong J, Zu X, Li Y, Mu W, Deng Y. Janus particles with tunable coverage of zinc oxide nanowires. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm03809a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Kizuka T, Kodama S, Matsuda T. Verification of unzipping models of electromigration in gold nanocontacts by in situ high-resolution transmission electron microscopy. NANOTECHNOLOGY 2010; 21:495706. [PMID: 21079293 DOI: 10.1088/0957-4484/21/49/495706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We observed in situ the electromigration process of gold (Au) nanocontacts (NCs) by high-resolution transmission electron microscopy. The structural dynamics of the interior and surfaces of the NCs were investigated at the atomic level. In particular, we directly verified the evidence of the unzipping model of electromigration with the in situ observation of surface-edge movement. The fundamental parameters of NCs, i.e., conductance and tensile force, were also measured during in situ lattice imaging of electromigration. Atoms migrating from the negative electrode accumulated at the most constricted regions of the NCs, leading to expansion. As a result, the NCs were compressed by the two electrodes. We demonstrated the magnitude of the force acting on the NCs during electromigration. The critical voltage of electromigration was approximately 80 mV, and the current density at the critical voltage was 60 TA m(-2). We found that Au nanogaps could be fabricated by applying this bias voltage to Au NCs.
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Affiliation(s)
- Tokushi Kizuka
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki, Japan.
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27
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Abstract
Molecular electronic devices currently serve as a platform for studying a variety of physical phenomena only accessible at the nanometer scale. One such phenomenon is the highly correlated electronic state responsible for the Kondo effect, manifested here as a "Kondo resonance" in the conductance. Because the Kondo effect results from strong electron-electron interactions, it is not captured by the usual quantum chemistry approaches traditionally applied to understand chemical electron transfer. In this review, we will discuss the origins and phenomenology of Kondo resonances observed in single-molecule devices, focusing primarily on the spin-1/2 Kondo state arising from a single unpaired electron. We explore the rich physical system of a single-molecule device, which offers a unique spectroscopic tool for investigating the interplay of emergent Kondo behavior and such properties as molecular orbital transitions and vibrational modes. We will additionally address more exotic systems, such as higher spin states in the Kondo regime, and we will review recent experimental advances in the ability to manipulate and exert control over these nanoscale devices.
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Affiliation(s)
- Gavin David Scott
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA.
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28
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Scott GD, Palacios JJ, Natelson D. Anomalous transport and possible phase transition in palladium nanojunctions. ACS NANO 2010; 4:2831-2837. [PMID: 20405906 DOI: 10.1021/nn1000172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Many phenomena in condensed matter are thought to result from competition between different ordered phases. Palladium is a paramagnetic metal close to both ferromagnetism and superconductivity and is, therefore, a potentially interesting material to consider. Nanoscale structuring of matter can modify relevant physical energy scales, leading to effects such as locally modified magnetic interactions. We present transport measurements in electromigrated palladium break junction devices showing the emergence at low temperatures of anomalous sharp features in the differential conductance. These features appear symmetrically in applied bias and exhibit a temperature dependence of their characteristic voltages reminiscent of a mean-field phase transition. The systematic variation of these voltages with zero bias conductance, together with density functional theory calculations illustrating the relationship between the magnetization of Pd and atomic coordination, suggests that the features may result from the onset of spontaneous magnetization in the nanojunction electrodes. We propose that the characteristic conductance features are related to inelastic tunneling involving magnetic excitations.
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Affiliation(s)
- Gavin D Scott
- Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
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29
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Jan van der Molen S, Liljeroth P. Charge transport through molecular switches. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:133001. [PMID: 21389503 DOI: 10.1088/0953-8984/22/13/133001] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We review the fascinating research on charge transport through switchable molecules. In the past decade, detailed investigations have been performed on a great variety of molecular switches, including mechanically interlocked switches (rotaxanes and catenanes), redox-active molecules and photochromic switches (e.g. azobenzenes and diarylethenes). To probe these molecules, both individually and in self-assembled monolayers (SAMs), a broad set of methods have been developed. These range from low temperature scanning tunneling microscopy (STM) via two-terminal break junctions to larger scale SAM-based devices. It is generally found that the electronic coupling between molecules and electrodes has a profound influence on the properties of such molecular junctions. For example, an intrinsically switchable molecule may lose its functionality after it is contacted. Vice versa, switchable two-terminal devices may be created using passive molecules ('extrinsic switching'). Developing a detailed understanding of the relation between coupling and switchability will be of key importance for both future research and technology.
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30
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Johnson SL, Sundararajan A, Hunley DP, Strachan DR. Memristive switching of single-component metallic nanowires. NANOTECHNOLOGY 2010; 21:125204. [PMID: 20203360 DOI: 10.1088/0957-4484/21/12/125204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Memristors have recently generated significant interest due to their potential use in nanoscale logic and memory devices. Of the four passive circuit elements, the memristor (a two-terminal hysteretic switch) has so far proved hard to fabricate out of a single material. Here we employ electromigration to create a reversible passive electrical switch, a memristive device, from a single-component metallic nanowire. To achieve resistive switching in a single-component structure we introduce a new class of memristors, devices in which the state variable of resistance is the system's physical geometry. By exploiting electromigration to reversibly alter the geometry, we repeatedly switch the resistance of single-component metallic nanowires between low and high states over many cycles. The reversible electromigration causes the nanowire to be cyclically narrowed to approximately 10 nm in width, resulting in a change in resistance by a factor of two. As a result, this work represents a potential route to the creation of nanoscale circuits from a single metallic element.
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Affiliation(s)
- S L Johnson
- Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506, USA
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31
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Kervennic YV, Kubatkin S. Fabrication of clean nanogaps using a combined electrochemical-chemical method. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2009; 5:2541-2544. [PMID: 19714734 DOI: 10.1002/smll.200900908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- Yann-Vaï Kervennic
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Göteborg, Sweden.
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32
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Yamada R. ELECTROCHEMISTRY 2009; 77:886-890. [DOI: 10.5796/electrochemistry.77.886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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33
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Feldman AK, Steigerwald ML, Guo X, Nuckolls C. Molecular electronic devices based on single-walled carbon nanotube electrodes. Acc Chem Res 2008; 41:1731-41. [PMID: 18798657 DOI: 10.1021/ar8000266] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
As the top-down fabrication techniques for silicon-based electronic materials have reached the scale of molecular lengths, researchers have been investigating nanostructured materials to build electronics from individual molecules. Researchers have directed extensive experimental and theoretical efforts toward building functional optoelectronic devices using individual organic molecules and fabricating metal-molecule junctions. Although this method has many advantages, its limitations lead to large disagreement between experimental and theoretical results. This Account describes a new method to create molecular electronic devices, covalently bridging a gap in a single-walled carbon nanotube (SWNT) with an electrically functional molecule. First, we introduce a molecular-scale gap into a nanotube by precise oxidative cutting through a lithographic mask. Now functionalized with carboxylic acids, the ends of the cleaved carbon nanotubes are reconnected with conjugated diamines to give robust diamides. The molecular electronic devices prepared in this fashion can withstand and respond to large environmental changes based on the functional groups in the molecules. For example, with oligoanilines as the molecular bridge, the conductance of the device is sensitive to pH. Similarly, using diarylethylenes as the bridge provides devices that can reversibly switch between conjugated and nonconjugated states. The molecular bridge can perform the dual task of carrying electrical current and sensing/recognition through biological events such as protein/substrate binding and DNA hybridization. The devices based on DNA can measure the difference in electrical properties of complementary and mismatched strands. A well-matched duplex DNA 15-mer in the gap exhibits a 300-fold lower resistance than a duplex with a GT or CA mismatch. This system provides an ultrasensitive way to detect single-nucleotide polymorphisms at the individual molecule level. Restriction enzymes can cleave certain cDNA strands assembled between the SWNT electrodes; therefore, these strands maintain their native conformation when bridging the ends of the SWNTs. This methodology for creating novel molecular circuits forges both literal and figurative connections between chemistry, physics, materials science, and biology and promises a new generation of integrated multifunctional sensors and devices.
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Affiliation(s)
- Alina K. Feldman
- Department of Chemistry and the Columbia University Center for Electronics of Molecular Nanostructures, Columbia University, New York, New York 10027
| | - Michael L. Steigerwald
- Department of Chemistry and the Columbia University Center for Electronics of Molecular Nanostructures, Columbia University, New York, New York 10027
| | - Xuefeng Guo
- Centre for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Colin Nuckolls
- Department of Chemistry and the Columbia University Center for Electronics of Molecular Nanostructures, Columbia University, New York, New York 10027
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34
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Prokopuk N, Son KA. Alligator clips to molecular dimensions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:374116. [PMID: 21694423 DOI: 10.1088/0953-8984/20/37/374116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Techniques for fabricating nanospaced electrodes suitable for studying electron tunneling through metal-molecule-metal junctions are described. In one approach, top contacts are deposited/placed on a self-assembled monolayer or Langmuir-Blodgett film resting on a conducting substrate, the bottom contact. The molecular component serves as a permanent spacer that controls and limits the electrode separations. The top contact can be a thermally deposited metal film, liquid mercury drop, scanning probe tip, metallic wire or particle. Introduction of the top contact can greatly affect the electrical conductance of the intervening molecular film by chemical reaction, exerting pressure, or simply migrating through the organic layer. Alternatively, vacant nanogaps can be fabricated and the molecular component subsequently inserted. Strategies for constructing vacant nanogaps include mechanical break junction, electromigration, shadow mask lithography, focused ion beam deposition, chemical and electrochemical plating techniques, electron-beam lithography, and molecular and atomic rulers. The size of the nanogaps must be small enough to allow the molecule to connect both leads and large enough to keep the molecules in a relaxed and undistorted state. A significant advantage of using vacant nanogaps in the construction of metal-molecule-metal devices is that the junction can be characterized with and without the molecule in place. Any electrical artifacts introduced by the electrode fabrication process are more easily deconvoluted from the intrinsic properties of the molecule.
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Affiliation(s)
- Nicholas Prokopuk
- NAVAIR Research Department, Chemistry Branch, China Lake, CA 93555-6100, USA
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35
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Ward DR, Scott GD, Keane ZK, Halas NJ, Natelson D. Electronic and optical properties of electromigrated molecular junctions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:374118. [PMID: 21694425 DOI: 10.1088/0953-8984/20/37/374118] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Electromigrated nanoscale junctions have proven very useful for studying electronic transport at the single-molecule scale. However, confirming that conduction is through precisely the molecule of interest and not some contaminant or metal nanoparticle has remained a persistent challenge, typically requiring a statistical analysis of many devices. We review how transport mechanisms in both electronic and optical measurements can be used to infer information about the nanoscale junction configuration. The electronic response to optical excitation is particularly revealing. We briefly discuss surface-enhanced Raman spectroscopy on such junctions, and present new results showing that currents due to optical rectification can provide a means of estimating the local electric field at the junction due to illumination.
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Affiliation(s)
- D R Ward
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
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36
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Roch N, Florens S, Bouchiat V, Wernsdorfer W, Balestro F. Quantum phase transition in a single-molecule quantum dot. Nature 2008; 453:633-7. [PMID: 18509439 DOI: 10.1038/nature06930] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Accepted: 03/18/2008] [Indexed: 11/09/2022]
Abstract
Quantum criticality is the intriguing possibility offered by the laws of quantum mechanics when the wave function of a many-particle physical system is forced to evolve continuously between two distinct, competing ground states. This phenomenon, often related to a zero-temperature magnetic phase transition, is believed to govern many of the fascinating properties of strongly correlated systems such as heavy-fermion compounds or high-temperature superconductors. In contrast to bulk materials with very complex electronic structures, artificial nanoscale devices could offer a new and simpler means of understanding quantum phase transitions. Here we demonstrate this possibility in a single-molecule quantum dot, where a gate voltage induces a crossing of two different types of electron spin state (singlet and triplet) at zero magnetic field. The quantum dot is operated in the Kondo regime, where the electron spin on the quantum dot is partially screened by metallic electrodes. This strong electronic coupling between the quantum dot and the metallic contacts provides the strong electron correlations necessary to observe quantum critical behaviour. The quantum magnetic phase transition between two different Kondo regimes is achieved by tuning gate voltages and is fundamentally different from previously observed Kondo transitions in semiconductor and nanotube quantum dots. Our work may offer new directions in terms of control and tunability for molecular spintronics.
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Affiliation(s)
- Nicolas Roch
- Institut Néel, CNRS and Université Joseph Fourier, BP 166, 38042 Grenoble cedex 9, France
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37
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Ulgut B, Abruña HD. Electron Transfer through Molecules and Assemblies at Electrode Surfaces. Chem Rev 2008; 108:2721-36. [DOI: 10.1021/cr068060w] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Burak Ulgut
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - Héctor D. Abruña
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
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38
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Abstract
We propose and demonstrate a voltage-pulse-induced electromigration technique, in which electromigration in a gold nanowire is induced for a short period of about 10 µs by applying a voltage pulse. A local temperature analysis and a controlled electromigration experiment in the presence of voltage pulses indicate successful control of this voltage-pulsed-induced electromigration. We also measured the current-voltage characteristics of the nanowire after the application of each single voltage pulse to investigate the stochastic behavior of electromigration. A pulse duration shorter than the thermal relaxation time of the nanowire would allow us to separately control the local temperature and driving force for electromigration.
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Affiliation(s)
- Toshiaki Hayashi
- NTT Basic Research Laboratories, NTT Corporation, 3-1, Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
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39
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Strachan DR, Johnston DE, Guiton BS, Datta SS, Davies PK, Bonnell DA, Johnson ATC. Real-time TEM imaging of the formation of crystalline nanoscale gaps. PHYSICAL REVIEW LETTERS 2008; 100:056805. [PMID: 18352410 DOI: 10.1103/physrevlett.100.056805] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Indexed: 05/26/2023]
Abstract
We present real-time transmission electron microscopy of nanogap formation by feedback controlled electromigration that reveals a remarkable degree of crystalline order. Crystal facets appear during feedback controlled electromigration indicating a layer-by-layer, highly reproducible electromigration process avoiding thermal runaway and melting. These measurements provide insight into the electromigration induced failure mechanism in sub-20 nm size interconnects, indicating that the current density at failure increases as the width decreases to approximately 1 nm.
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Affiliation(s)
- Douglas R Strachan
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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40
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Tsutsui M, Shoji K, Taniguchi M, Kawai T. Formation and self-breaking mechanism of stable atom-sized junctions. NANO LETTERS 2008; 8:345-9. [PMID: 18095741 DOI: 10.1021/nl073003j] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The self-breaking mechanism of gold junctions is studied by investigating stability of the atom-sized contacts. The single atom contact lifetime increases from about 0.02 to 200 s upon decreasing the junction stretching speed, while at the same time, the breaking force diminishes logarithmically. We find that the junction self-breaking processes involve sufficient atomic rearrangements, which thereby allow complete self-compensation of externally introduced strain at 0.8 pm/s. The present results have important implications on fabrication of stable single molecule junctions.
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Affiliation(s)
- Makusu Tsutsui
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
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41
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Luo K, Chae DH, Yao Z. Room-temperature single-electron transistors using alkanedithiols. NANOTECHNOLOGY 2007; 18:465203. [PMID: 21730471 DOI: 10.1088/0957-4484/18/46/465203] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have fabricated single-electron transistors by alkanedithiol molecular self-assembly. The devices consist of spontaneously formed ultrasmall Au nanoparticles linked by alkanedithiols to nanometer-spaced Au electrodes created by electromigration. The devices reproducibly exhibit addition energies of a few hundred meV, which enables the observation of single-electron tunneling at room temperature. At low temperatures, tunneling through discrete energy levels in the Au nanoparticles is observed, which is accompanied by the excitations of molecular vibrations at large bias voltage.
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Affiliation(s)
- Kang Luo
- Department of Physics, The University of Texas at Austin, Austin, TX 78712, USA. Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, Austin, TX 78712, USA. Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA
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Johnston DE, Strachan DR, Johnson ATC. Parallel fabrication of nanogap electrodes. NANO LETTERS 2007; 7:2774-7. [PMID: 17696560 DOI: 10.1021/nl0713169] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We have developed a technique for simultaneously fabricating large numbers of nanogaps in a single processing step using feedback-controlled electromigration. Parallel nanogap formation is achieved by a balanced simultaneous process that uses a novel arrangement of nanoscale shorts between narrow constrictions where the nanogaps form. Because of this balancing, the fabrication of multiple nanoelectrodes is similar to that of a single nanogap junction. The technique should be useful for constructing complex circuits of molecular-scale electronic devices.
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Affiliation(s)
- Danvers E Johnston
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Tang J, Wang Y, Klare J, Tulevski G, Wind S, Nuckolls C. Encoding Molecular-Wire Formation within Nanoscale Sockets. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200604398] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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44
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Tang J, Wang Y, Klare JE, Tulevski GS, Wind SJ, Nuckolls C. Encoding Molecular-Wire Formation within Nanoscale Sockets. Angew Chem Int Ed Engl 2007; 46:3892-5. [PMID: 17342783 DOI: 10.1002/anie.200604398] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jinyao Tang
- Department of Chemistry and The Center for Electron Transport in Molecular Nanostructures, Columbia University, New York, NY 10027, USA
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45
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Taychatanapat T, Bolotin KI, Kuemmeth F, Ralph DC. Imaging electromigration during the formation of break junctions. NANO LETTERS 2007; 7:652-6. [PMID: 17305400 DOI: 10.1021/nl062631i] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Using a scanning electron microscope, we make real-time movies of gold nanowires during the process of electromigration. We confirm the importance of using a small series resistance when employing electromigration to make controlled nanometer-scale gaps suitable for molecular-electronics studies. We are also able to estimate the effective temperature experienced by molecular adsorbates on the nanowire during the electromigration process.
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Affiliation(s)
- Thiti Taychatanapat
- Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA
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46
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Jo MH, Grose JE, Baheti K, Deshmukh MM, Sokol JJ, Rumberger EM, Hendrickson DN, Long JR, Park H, Ralph DC. Signatures of molecular magnetism in single-molecule transport spectroscopy. NANO LETTERS 2006; 6:2014-20. [PMID: 16968018 DOI: 10.1021/nl061212i] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We report single-molecule-transistor measurements on devices incorporating magnetic molecules. By studying the electron-tunneling spectrum as a function of magnetic field, we are able to identify signatures of magnetic states and their associated magnetic anisotropy. A comparison of the data to simulations also suggests that sequential electron tunneling may enhance the magnetic relaxation of the magnetic molecule.
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Affiliation(s)
- Moon-Ho Jo
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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47
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Smith RK, Nanayakkara SU, Woehrle GH, Pearl TP, Blake MM, Hutchison JE, Weiss PS. Spectral Diffusion in the Tunneling Spectra of Ligand-Stabilized Undecagold Clusters. J Am Chem Soc 2006; 128:9266-7. [PMID: 16848426 DOI: 10.1021/ja061040r] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report diffusion in the tunneling spectra of isolated, ligand-stabilized undecagold (Au11) clusters immobilized by attachment to alpha,omega-alkanedithiolate tethers inserted into alkanethiolate self-assembled monolayers. We use scanning tunneling microscopy and spectroscopy at cryogenic (UHV, 4 K) conditions to measure these clusters' conductance with complete control of their chemical and physical environment; additionally, thermal broadening of their electronic states as well as their mobility is minimized. At low temperature, the Au11 clusters demonstrate Coulomb blockade behavior, with zero-conductance gaps resulting from quantum size effects. Surprisingly, chemically identical and even single particles produced different families of tunneling spectra, comparable to previous results for heterogeneous distributions of particles. We hypothesize that, while these particles are chemically attached to the surface of the SAM for measurement, these assemblies may still be sufficiently dynamic to affect their transport properties significantly.
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Affiliation(s)
- Rachel K Smith
- Departments of Chemistry and Physics, 104 Davey Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802-6300, USA
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48
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Heersche HB, de Groot Z, Folk JA, van der Zant HSJ, Romeike C, Wegewijs MR, Zobbi L, Barreca D, Tondello E, Cornia A. Electron transport through single Mn12 molecular magnets. PHYSICAL REVIEW LETTERS 2006; 96:206801. [PMID: 16803192 DOI: 10.1103/physrevlett.96.206801] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Indexed: 05/10/2023]
Abstract
We report transport measurements through a single-molecule magnet, the Mn12 derivative [Mn12O12(O2C-C6H4-SAc)16(H2O)4], in a single-molecule transistor geometry. Thiol groups connect the molecule to gold electrodes that are fabricated by electromigration. Striking observations are regions of complete current suppression and excitations of negative differential conductance on the energy scale of the anisotropy barrier of the molecule. Transport calculations, taking into account the high-spin ground state and magnetic excitations of the molecule, reveal a blocking mechanism of the current involving nondegenerate spin multiplets.
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Affiliation(s)
- H B Heersche
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
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Natelson D, Yu LH, Ciszek JW, Keane ZK, Tour JM. Single-molecule transistors: Electron transfer in the solid state. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2005.11.030] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Strachan DR, Smith DE, Fischbein MD, Johnston DE, Guiton BS, Drndić M, Bonnell DA, Johnson AT. Clean electromigrated nanogaps imaged by transmission electron microscopy. NANO LETTERS 2006; 6:441-4. [PMID: 16522038 DOI: 10.1021/nl052302a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Electromigrated nanogaps have shown great promise for use in molecular scale electronics. We have fabricated nanogaps on free-standing transparent SiN(x) membranes which permit the use of transmission electron microscopy (TEM) to image the gaps. The electrodes are formed by extending a recently developed controlled electromigration procedure and yield a nanogap with approximately 5 nm separation clear of any apparent debris. The gaps are stable, on the order of hours as measured by TEM, but over time (months) relax to about 20 nm separation determined by the surface energy of the Au electrodes. A major benefit of electromigrated nanogaps on SiN(x) membranes is that the junction pinches in away from residual metal left from the Au deposition which could act as a parasitic conductance path. This work has implications to the design of clean metallic electrodes for use in nanoscale devices where the precise geometry of the electrode is important.
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Affiliation(s)
- Douglas R Strachan
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, 19104, USA.
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