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Bennett RX, Hendrickson JR, Bergfield JP. Quantum Interference Enhancement of the Spin-Dependent Thermoelectric Response. ACS NANO 2024; 18:11876-11885. [PMID: 38651504 PMCID: PMC11080465 DOI: 10.1021/acsnano.4c01297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/01/2024] [Accepted: 04/05/2024] [Indexed: 04/25/2024]
Abstract
We investigate the influence of quantum interference (QI) and broken spin-symmetry on the thermoelectric response of node-possessing junctions, finding a dramatic enhancement of the spin-thermopower (Ss), figure-of-merit (ZsT), and maximum thermodynamic efficiency (ηsmax) caused by destructive QI. Using many-body and single-particle methods, we calculate the response of 1,3-benzenedithiol and cross-conjugated molecule-based junctions subject to an applied magnetic field, finding nearly universal behavior over a range of junction parameters with Ss, ZsT, and reaching peak values of 2 π / 3 ( k / e ) , 1.51, and 28% of Carnot efficiency, respectively. We also find that the quantum-enhanced spin-response is spectrally broad, and the field required to achieve peak efficiency scales with temperature. The influence of off-resonant thermal channels (e.g., phonon heat transport) on this effect is also investigated.
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Affiliation(s)
- Runa X. Bennett
- Department
of Physics, Illinois State University, Normal, Illinois 61790, United States
| | - Joshua R. Hendrickson
- Air
Force Research Laboratory, Sensors Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Justin P. Bergfield
- Department
of Physics, Illinois State University, Normal, Illinois 61790, United States
- Department
of Chemistry, Illinois State University, Normal, Illinois 61790, United States
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2
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Hu Y, Liu S, Huang J, Li X, Li Q. Gate-Tunable Spin Seebeck Effect and Pure Spin Current Generation in Molecular Junctions Based on Bipolar Magnetic Molecules. NANO LETTERS 2023; 23:7890-7896. [PMID: 37602760 DOI: 10.1021/acs.nanolett.3c01702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Generating pure spin currents is very desirable in spintronics, as it provides a promising way to substantially reduce Joule heating and achieve ultrahigh integration density. However, to date, most spintronic devices exhibit spin currents that are accompanied by charge currents. The generation of pure spin currents on the nanoscale, particularly at the single-molecule level, remains challenging. Here, we propose that by exploiting our recently reported bipolar magnetic molecules (BMMs) as the core component of single-molecule devices, where the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) come from different spin channels, the generation of pure spin currents can be easily realized via the spin Seebeck effect (SSE) with applied temperature gradient. Moreover, the spin Seebeck coefficient can be modulated over a wide range by applying an external gate voltage. The proposal is verified through first-principles calculations on two BMM-based molecular junctions.
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Affiliation(s)
- Yujie Hu
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Shanshan Liu
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Jing Huang
- School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, Anhui 230601, People's Republic of China
| | - Xingxing Li
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Qunxiang Li
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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3
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Zhang Z, Yin F, Wang C, Li Z, Liu H. Magnetic field-controlled spin-dependent thermoelectric current in a single-molecule magnet transistor. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:235302. [PMID: 33784643 DOI: 10.1088/1361-648x/abf385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Abstract
Control of the charge, spin, and heat currents in thermoelectric devices is an interesting research field that is currently experiencing a burst of activity. In this work, a new type of spin-current generator is proposed that consists of a single-molecule magnet sandwiched between a pair of nonmagnetic electrodes. By applying an external magnetic field, this tunneling junction can generate a 100% spin-polarized current via thermoelectric effects, and the flow direction and spin polarization can be changed by adjusting the gate voltage or magnetic field. Moreover, regardless of whether the external magnetic field exists, the thermoelectric current is always highly spin polarized and can be switched by using different gate voltage windows. This molecular electrical device can be realized with current technologies and may have practical use in spin caloritronics and quantum information processing.
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Affiliation(s)
- Zhengzhong Zhang
- Faculty of Mathematics and Physics, Huaiyin Institute of Technology, Huaian 223003, People's Republic of China
| | - Fan Yin
- Faculty of Mathematics and Physics, Huaiyin Institute of Technology, Huaian 223003, People's Republic of China
| | - Chao Wang
- Faculty of Mathematics and Physics, Huaiyin Institute of Technology, Huaian 223003, People's Republic of China
| | - Zhongwen Li
- Faculty of Mathematics and Physics, Huaiyin Institute of Technology, Huaian 223003, People's Republic of China
| | - Hao Liu
- Faculty of Mathematics and Physics, Huaiyin Institute of Technology, Huaian 223003, People's Republic of China
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4
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Manaparambil A, Weymann I. Spin Seebeck effect of correlated magnetic molecules. Sci Rep 2021; 11:9192. [PMID: 33911112 PMCID: PMC8080696 DOI: 10.1038/s41598-021-88373-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/09/2021] [Indexed: 11/15/2022] Open
Abstract
In this paper we investigate the spin-resolved thermoelectric properties of strongly correlated molecular junctions in the linear response regime. The magnetic molecule is modeled by a single orbital level to which the molecular core spin is attached by an exchange interaction. Using the numerical renormalization group method we analyze the behavior of the (spin) Seebeck effect, heat conductance and figure of merit for different model parameters of the molecule. We show that the thermopower strongly depends on the strength and type of the exchange interaction as well as the molecule's magnetic anisotropy. When the molecule is coupled to ferromagnetic leads, the thermoelectric properties reveal an interplay between the spin-resolved tunneling processes and intrinsic magnetic properties of the molecule. Moreover, in the case of finite spin accumulation in the leads, the system exhibits the spin Seebeck effect. We demonstrate that a considerable spin Seebeck effect can develop when the molecule exhibits an easy-plane magnetic anisotropy, while the sign of the spin thermopower depends on the type and magnitude of the molecule's exchange interaction.
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Affiliation(s)
- Anand Manaparambil
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland.
| | - Ireneusz Weymann
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland
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5
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Marin R, Brunet G, Murugesu M. Multifunktionale Einzelmolekülmagnete auf Lanthanoidbasis in neuem Licht. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201910299] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Riccardo Marin
- Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N 6N5 Kanada
| | - Gabriel Brunet
- Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N 6N5 Kanada
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N 6N5 Kanada
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6
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Marin R, Brunet G, Murugesu M. Shining New Light on Multifunctional Lanthanide Single‐Molecule Magnets. Angew Chem Int Ed Engl 2020; 60:1728-1746. [DOI: 10.1002/anie.201910299] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/02/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Riccardo Marin
- Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N 6N5 Canada
| | - Gabriel Brunet
- Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N 6N5 Canada
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences University of Ottawa Ottawa Ontario K1N 6N5 Canada
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7
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Yang C, Qin A, Tang BZ, Guo X. Fabrication and functions of graphene-molecule-graphene single-molecule junctions. J Chem Phys 2020; 152:120902. [PMID: 32241145 DOI: 10.1063/1.5144275] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The past two decades have witnessed increasingly rapid advances in the field of single-molecule electronics, which are expected to overcome the limitation of the miniaturization of silicon-based microdevices, thus promoting the development of device manufacturing technologies and characterization means. In addition to this, they can enable us to investigate the intrinsic properties of materials at the atomic- or molecular-length scale and probe new phenomena that are inaccessible in ensemble experiments. In this perspective, we start from a brief introduction on the manufacturing method of graphene-molecule-graphene single-molecule junctions (GMG-SMJs). Then, we make a description on the remarkable functions of GMG-SMJs, especially on the investigation of single-molecule charge transport and dynamics. Finally, we conclude by discussing the main challenges and future research directions of molecular electronics.
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Affiliation(s)
- Caiyao Yang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou 510640, China
| | - Anjun Qin
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou 510640, China
| | - Ben Zhong Tang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou 510640, China
| | - 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
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8
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Li XS, Wang C, Deng MX, Duan HJ, Fu PH, Wang RQ, Sheng L, Xing DY. Photon-Induced Weyl Half-Metal Phase and Spin Filter Effect from Topological Dirac Semimetals. PHYSICAL REVIEW LETTERS 2019; 123:206601. [PMID: 31809106 DOI: 10.1103/physrevlett.123.206601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Recently discovered Dirac semimetals (DSMs) with two Dirac nodes, such as Na_{3}Bi and Cd_{2}As_{3}, are regarded as carrying the Z_{2} topological charge in addition to the chiral charge. We study the Floquet phase transition of Z_{2} topological DSMs subjected to a beam of circularly polarized light. Owing to the resulting interplay of the chiral and Z_{2} charges, the Weyl nodes are not only chirality dependent but also spin dependent, which constrains the behavior in creation and annihilation of the pair of Weyl nodes. Interestingly, we find a novel phase: One spin band is in the Weyl semimetal phase while the other is in the insulator phase, and we dub it the Weyl half-metal (WHM) phase. We further study the spin-dependent transport in a Dirac-Weyl semimetal junction and find a spin filter effect as a fingerprint of the existence of the WHM phase. The proposed spin filter effect, based on the WHM bulk band, is highly tunable in a broad parameter regime and robust against magnetic disorder, which is expected to overcome the shortcomings of the previously proposed spin filter based on the topological edge or surface states. Our results offer a unique opportunity to explore the potential applications of topological DSMs in spintronics.
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Affiliation(s)
- Xiao-Shi Li
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, SPTE, South China Normal University, Guangzhou 510006, China
| | - Chen Wang
- Lab for Computational Imaging Technology and Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing 210023, China
| | - Ming-Xun Deng
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, SPTE, South China Normal University, Guangzhou 510006, China
| | - Hou-Jian Duan
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, SPTE, South China Normal University, Guangzhou 510006, China
| | - Pei-Hao Fu
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, SPTE, South China Normal University, Guangzhou 510006, China
| | - Rui-Qiang Wang
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, SPTE, South China Normal University, Guangzhou 510006, China
| | - L Sheng
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
| | - D Y Xing
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
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9
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Zimbovskaya NA. Thermoelectric efficiency of single-molecule junctions with long molecular linkers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:305301. [PMID: 29911988 DOI: 10.1088/1361-648x/aacd3a] [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
We report results of theoretical studies of thermoelectric efficiency of single-molecule junctions with long molecular linkers. The linker is simulated by a chain of identical sites described using a tight-binding model. It is shown that thermoelectric figure of merit ZT strongly depends on the bridge length, being controlled by the lineshape of electron transmission function within the tunnel energy range corresponding to HOMO/LUMO transport channel. Using the adopted model we demonstrate that ZT may significantly increase as the linker lengthens, and that gateway states on the bridge (if any) may noticeably affect the length-dependent ZT. Temperature dependences of ZT for various bridge lengths are analyzed. It is shown that broad minima emerge in ZT versus temperature curves whose positions are controlled by the bridge lengths.
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Affiliation(s)
- Natalya A Zimbovskaya
- Department of Physics and Electronics, University of Puerto Rico-Humacao, CUH Station, Humacao, PR 00791, United States of America
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10
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Gehring P, Harzheim A, Spièce J, Sheng Y, Rogers G, Evangeli C, Mishra A, Robinson BJ, Porfyrakis K, Warner JH, Kolosov OV, Briggs GAD, Mol JA. Field-Effect Control of Graphene-Fullerene Thermoelectric Nanodevices. NANO LETTERS 2017; 17:7055-7061. [PMID: 28982009 DOI: 10.1021/acs.nanolett.7b03736] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although it was demonstrated that discrete molecular levels determine the sign and magnitude of the thermoelectric effect in single-molecule junctions, full electrostatic control of these levels has not been achieved to date. Here, we show that graphene nanogaps combined with gold microheaters serve as a testbed for studying single-molecule thermoelectricity. Reduced screening of the gate electric field compared to conventional metal electrodes allows control of the position of the dominant transport orbital by hundreds of meV. We find that the power factor of graphene-fullerene junctions can be tuned over several orders of magnitude to a value close to the theoretical limit of an isolated Breit-Wigner resonance. Furthermore, our data suggest that the power factor of an isolated level is only given by the tunnel coupling to the leads and temperature. These results open up new avenues for exploring thermoelectricity and charge transport in individual molecules and highlight the importance of level alignment and coupling to the electrodes for optimum energy conversion in organic thermoelectric materials.
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Affiliation(s)
- Pascal Gehring
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Achim Harzheim
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Jean Spièce
- Physics Department, Lancaster University , Lancaster LA1 4YB, United Kingdom
| | - Yuewen Sheng
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Gregory Rogers
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | | | - Aadarsh Mishra
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Benjamin J Robinson
- Physics Department, Lancaster University , Lancaster LA1 4YB, United Kingdom
- Materials Science Institute, Lancaster University , Lancaster, LA1 4YW, United Kingdom
| | - Kyriakos Porfyrakis
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Jamie H Warner
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Oleg V Kolosov
- Physics Department, Lancaster University , Lancaster LA1 4YB, United Kingdom
| | - G Andrew D Briggs
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
| | - Jan A Mol
- Department of Materials, University of Oxford , 16 Parks Road, Oxford OX1 3PH, United Kingdom
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11
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Xue N, Xie H, Wang Z, Liang JQ. Spin-polarization inversion of transport current and tunnel magnetoresistance through a non-collinear uniaxial-molecule-magnet dimer junction with electrode magnetization. RSC Adv 2016. [DOI: 10.1039/c6ra03515a] [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] Open
Abstract
In this paper, we study quantum transport through a tunnel junction embedded with a non-collinear uniaxial molecule-magnet-dimer with the magnetization of ferromagnetic electrodes.
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Affiliation(s)
- Naitao Xue
- Institute of Theoretical Physics and Department of Physics
- Shanxi University
- China
| | - Haiqing Xie
- Department of Physics
- Taiyuan Normal University
- China
| | - Zhimei Wang
- Institute of Theoretical Physics and Department of Physics
- Shanxi University
- China
| | - J.-Q. Liang
- Institute of Theoretical Physics and Department of Physics
- Shanxi University
- China
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12
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Niu P, Shi YL, Sun Z, Nie YH, Luo HG. Kondo peak splitting and Kondo dip induced by a local moment. Sci Rep 2015; 5:18021. [PMID: 26658128 PMCID: PMC4675084 DOI: 10.1038/srep18021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 11/10/2015] [Indexed: 11/09/2022] Open
Abstract
Many features like spin-orbit coupling, bias and magnetic fields applied, and so on, can strongly influence the Kondo effect. One of the consequences is Kondo peak splitting. However, Kondo peak splitting led by a local moment has not been investigated systematically. In this research we study theoretically electronic transport through a single-level quantum dot exchange coupled to a local magnetic moment in the Kondo regime. We focus on the Kondo peak splitting induced by an anisotropic exchange coupling between the quantum dot and the local moment, which shows rich splitting behavior. We consider the cases of a local moment with S = 1/2 and S = 1. The longitudinal (z-component) coupling plays a role of multivalued magnetic fields and the transverse (x, y-components) coupling lifts the degeneracy of the quantum dot, both of which account for the fine Kondo peak splitting structures. The inter-level or intra-level transition processes are identified in detail. Moreover, we find a Kondo dip at the Fermi level under the proper parameters. The possible experimental observations of these theoretical results should deepen our understanding of Kondo physics.
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Affiliation(s)
- Pengbin Niu
- Institute of Solid State Physics and Department of Physics, Shanxi Datong University, Datong 037009, China.,Shanxi Provincial Key Laboratory of micro-structural electromagnetic functional materials, Datong 037009, China
| | - Yun-Long Shi
- Institute of Solid State Physics and Department of Physics, Shanxi Datong University, Datong 037009, China
| | - Zhu Sun
- Institute of Solid State Physics and Department of Physics, Shanxi Datong University, Datong 037009, China
| | - Yi-Hang Nie
- Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, China
| | - Hong-Gang Luo
- Center for Interdisciplinary Studies &Key Laboratory for Magnetism and Magnetic Materials of the MoE, Lanzhou University, Lanzhou 730000, China.,Beijing Computational Science Research Center, Beijing 100084, China
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13
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Cui A, Liu Z, Dong H, Wang Y, Zhen Y, Li W, Li J, Gu C, Hu W. Single grain boundary break junction for suspended nanogap electrodes with gapwidth down to 1-2 nm by focused ion beam milling. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:3002-6. [PMID: 25854513 DOI: 10.1002/adma.201500527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 03/17/2015] [Indexed: 05/21/2023]
Abstract
Single grain boundary junctions are used for the fabrication of suspended nanogap electrodes with a gapwidth down to 1-2 nm through the break of such junctions by focused ion beam (FIB) milling. With advantages of stability and no debris, such nanogap electrodes are suitable for single molecular electronic device construction.
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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, China
| | - Zhe Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Huanli Dong
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yujin Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yonggang Zhen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wuxia Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Junjie Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Changzhi Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wenping Hu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) & Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, China
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14
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Lu X, Wang JS, Morrel WG, Ni X, Wu CQ, Li B. Thermoelectric effect in Aharonov-Bohm structures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:035301. [PMID: 25537848 DOI: 10.1088/0953-8984/27/3/035301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The thermoelectric effects of a single Aharonov-Bohm (SAB) ring and coupled double Aharonov-Bohm (DAB) rings have been investigated on a theoretical basis, taking into account the contributions of both electrons and phonons to the transport process by using the nonequilibrium Green's function technique. The thermoelectric figure of merit of the coupled DAB rings cannot be predicted directly by combining the values of two SAB ring systems due to the contribution of electron-phonon interaction to coupling between the two sites connecting the rings. We find that thermoelectric efficiency can be optimized by modulating the phases of the magnetic flux threading the two rings.
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Affiliation(s)
- Xin Lu
- Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542, Republic of Singapore
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15
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Ultrahigh spin thermopower and pure spin current in a single-molecule magnet. Sci Rep 2014; 4:4128. [PMID: 24549224 PMCID: PMC3928577 DOI: 10.1038/srep04128] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/30/2014] [Indexed: 11/30/2022] Open
Abstract
Using the non-equilibrium Green's function (NEGF) formalism within the sequential regime, we studied ultrahigh spin thermopower and pure spin current in single-molecule magnet(SMM), which is attached to nonmagnetic metal wires with spin bias and angle (θ) between the easy axis of SMM and the spin orientation in the electrodes. A pure spin current can be generated by tuning the gate voltage and temperature difference with finite spin bias and the arbitrary angle except of . In the linear regime, large thermopower can be obtained by modifying Vg and the angles (θ). These results are useful in fabricating and advantaging SMM devices based on spin caloritronics.
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16
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Golsanamlou Z, Tagani MB, Soleimani HR. Spin Thermoelectric Properties of Polythiophene Molecular Junction. MACROMOL THEOR SIMUL 2014. [DOI: 10.1002/mats.201300157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Zahra Golsanamlou
- Department of Physics; University of Guilan; P.O.Box 41335-1914 Rasht Iran
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17
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Dubi Y. The effect of fluctuations, thermal and otherwise, on the temperature dependence of thermopower in aromatic chain single-molecule junctions. J Chem Phys 2013; 138:114706. [DOI: 10.1063/1.4795496] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ying Y, Jin G. Nonlocal tunnel magnetoresistance and thermal rectification effect in a nanoscale three-terminal junction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:495304. [PMID: 23148042 DOI: 10.1088/0953-8984/24/49/495304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigate thermally driven electronic transport through a quantum dot (QD) coupled to two ferromagnetic leads and one normal-metallic lead. The effect of spin accumulation and temperature bias on the tunnel magnetoresistance (TMR) is examined. We obtain a nonlocal negative TMR, which also exhibits a rectification effect as a function of the QD level modulated by a gate voltage. For a negative QD level, the TMR is zero, and the TMR is negative for a positive QD level. This effect arises from the interplay of the spin accumulation and thermoelectric transport, which detects the sign reversal of spin accumulation in the QD. In addition, our system can also be used as a spin current generator.
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Affiliation(s)
- Yibo Ying
- Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, People's Republic of China.
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Wysokiński KI. Thermoelectric transport in the three terminal quantum dot. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:335303. [PMID: 22836027 DOI: 10.1088/0953-8984/24/33/335303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The thermoelectric transport in the system composed of a quantum dot in contact with superconducting, ferromagnetic and normal metal electrodes has been studied. Such a system can support pure spin current in the normal electrode. In the limit of a large superconducting gap and weak coupling between the dot and the electrodes we investigate the sub-gap charge and spin transport via Andreev mechanism using the standard master equation technique, which is known to be valid in the sequential tunnelling regime. The Zeeman splitting of the dot level induces pure spin current in the ferromagnetic electrode under an appropriate bias. This opens a novel possibility to switch the spin current between two electrodes by electric means. The calculated spin and charge thermopower coefficients attain very large values, of the order of a few hundreds μV K(-1), and show similar dependences on the position of the on-dot energy level and temperature.
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Affiliation(s)
- Karol Izydor Wysokiński
- Institute of Physics, M Curie-Skłodowska University, Radziszewskiego 10, Pl 20-031 Lublin, Poland.
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Lin W, Hehn M, Chaput L, Negulescu B, Andrieu S, Montaigne F, Mangin S. Giant spin-dependent thermoelectric effect in magnetic tunnel junctions. Nat Commun 2012; 3:744. [DOI: 10.1038/ncomms1748] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 02/13/2012] [Indexed: 11/09/2022] Open
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Li Y, Zhou G, Wu J, Duan W. Electronic and magnetic properties of early transition-metal substituted iron-cyclopentadienyl sandwich molecular wires: parity-dependent half-metallicity. J Chem Phys 2011; 135:014702. [PMID: 21744909 DOI: 10.1063/1.3604817] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electronic and magnetic properties of early transition metals (V, Ti, Sc)-Fe(k)Cp(k + 1) sandwich molecular wires (SMWs) are investigated by means of ab initio calculations. It is found that all SMWs favor a ferromagnetic ground state. Significantly, V-Fe(k)Cp(k + 1) SMWs are either half-metallic or semiconducting, dependent upon the parity (even or odd) of the number (k) of Fe atoms in the unit cell of SMWs. This parity oscillation of conductive properties results from the combined effects of the band-folding and gap-opening at the Brillouin-zone boundary of one-dimensional materials. In contrast, Sc-Fe(k)Cp(k + 1) and Ti-Fe(k)Cp(k + 1) SMWs are always semiconducting. Our work may open up the way toward half metal/semiconductor heterostructures with perfect atomic interface.
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Affiliation(s)
- Yuanchang Li
- Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
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Fransson J, Galperin M. Spin seebeck coefficient of a molecular spin pump. Phys Chem Chem Phys 2011; 13:14350-7. [DOI: 10.1039/c1cp20720b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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