Spin transport calculation for thiol-ended  single-molecule magnetic junction

以作者查詢圖書館館藏

、以作者查詢臺灣博碩士

、以作者查詢全國書目

、勘誤回報

、線上人數：9

、訪客IP：3.15.219.217

姓名

林承風(Cheng-Feng Lin) 查詢紙本館藏

畢業系所

物理學系

論文名稱

(Spin transport calculation for thiol-ended single-molecule magnetic junction)

相關論文

★ Stretching effect on the spin transport properties of single molecular junctions: A first-principle study	★ First-principles study in wurtzite InN bulk, thin film, and nanobelt
★ The interfacial effect on spin-transfer torque in single molecular magnetic junctions: A first-principles study	★ Combined first-principles and tight-binding Hamiltonian study of Fe-MgO-Fe magnetic tunnel junctions
★ Anchoring Effect on Spin Transport in Amine-Ended Single-Molecule Magnetic Junctions: A First-Principles Study	★ Analytic derivation for spin-transfer properties in magnetic tunnel junctions
★ Simulation for Cu-platted Front Side Metallization of Si-based Solar Cell	★ 利用單能階緊密鍵結模型計算磁性穿隧接合的自旋傳輸特性
★ Electronic and Spin Transport Properties of Fe/MgO/Fe Magnetic Tunnel Junction: Combined First-Principles Calculation and TB-NEGF Method	★ First-principles study in structural and elec-tronic properties of FeBaTiO3Fe multiferroic tunneling junction
★ Effect of contact geometry on the spin transfer calculation in amine-ended single-molecule magnetic junctions	★ Spin Transport Properties in Magnetic Heterojunctions: Analytical derivation in Green’s function and Multi-reflection process
★ Modification of Distributional Exact Diagonalization Approach for Single Impurity Anderson Model	★ Strain-Induced Magnetic-Nonmagnetic Transition in PtSe2 Nanoribbon: A First-Principles Study
★ 具電阻切換行為之氧化鋁磁性穿隧接面中低頻雜訊與傳輸機制研究	★ Understanding Oscillatory Domain Wall Motion via Spin Waves Theory

檔案

[Endnote RIS 格式]

[Bibtex 格式]

[相關文章]

[文章引用]

[完整記錄]

[館藏目錄]

[檢視]

[下載]

本電子論文使用權限為同意立即開放。
已達開放權限電子全文僅授權使用者為學術研究之目的，進行個人非營利性質之檢索、閱讀、列印。
請遵守中華民國著作權法之相關規定，切勿任意重製、散佈、改作、轉貼、播送，以免觸法。

摘要(中)

我們利用第一原理計算方法，先由以密度泛函理論為基礎的Quantum ESPRESSO 程序優化單一分子隧結 Ni/1,4-alkanedithiol(ADT)/Ni的結構，然後增加右邊Ni adatom與電極間的距離，進行結構優化，再重複以上步驟來模擬實驗上拉伸的過程，直到找到此單一分子隧結模型的斷裂點。我們接者再由應用了非平衡格林函數結合密度泛函理論與廣義梯度近似方法來計算在斷裂點時的projected density of states與transmission spectrum. 與應力相關的自旋極化穿隧頻譜可以透過Ni adatom的拓寬的自旋向上PDOS結合高低不平的自旋向下PDOS來了解。因為中間的以σ鍵為主的ADT分子是導電性較差的，以及由透過Ni adatom的直接穿隧主導穿隧機率。我們進一步計算了在斷裂點的電流-電壓特性以及磁阻率。令人驚訝的，在拉伸下對於導電性較差的以σ鍵為主的ADT單一分子接面的磁阻率值可達到至200%。

摘要(英)

We employed the density-functional theory (DFT) within the generalized approximations (GGA) in the PBE form, to simulate the Ni/1,4-alkanedithiol(ADT)/Ni single-molecule magnetic junction under stretching process. The junction is stretched by increasing the distance between two Ni nanowires in small steps, optimize it again, and continue to do so, until the junction breaks down. The First-principle spin transport calculation is based on the non-equilibrium Green’s functions formalism and the DFT approach. The strain dependence of spin-polarized transmission spectra can be understood by the broad spin-up PDOS combined with the spiky spin-down PDOS of Ni adatom. This is because the central σ-saturated ADT molecule is less conductive and the transmission probability is dominated by the direct tunneling via the Ni adatom. We further calculated the I-V characteristic of breaking point and get the magnetoresisitance (MR). Surprisingly, the giant value about 200% and the bias-induced of MR can be found in this less conductive σ-saturated Ni/1,4-alkanedithiol(ADT)/Ni single molecular junction under the stretching.

關鍵字(中)

★ 單分子通道
★ 磁阻
★ 自旋傳輸
★ 第一原理計算

關鍵字(英)

★ single molecular junctions
★ magnetoresistance
★ spin transport
★ first-principles calculation

論文目次

Chapter 1 Introduction 1
Chapter 2 Theory 7
2.1 Density Function Theory 7
2.1.1 Born-Oppenheimer Approximation 8
2.1.2 The Hohenberg-Kohn Theorem 9
2.1.3 The Kohn-Sham Equation 11
2.1.4 Exchange-Correlation Energy Functionals 16
Local Density Approximation (LDA) 16
Generalized Gradient Approximation (GGA)18
2.1.5 Pseudopotential Method 19
2.1.6 Basis Functions 21
2.2 Non-Equilibrium Green’s Function Method 21
2.2.1 The NEGF formalism 22
Chapter 3 Computational Details 29
3.1 Structural Geometry 29
3.2 Parameters for Structural Relaxation Calculation 30
3.3 Parameters for Spin Transport Calculation 32
Chapter 4 Results and Discussion 34
4.1 Structural Relaxation during Stretching 37
4.2 Spin-Transport Properties 37
4.3 Spin-Polarized Current and Magnetoresistance 43
Chapter 5 Summary 52
References 53

參考文獻

[1] M. N. Baibich, J. M. Broto, A. Fert, F. N. Van Dau, F. Petroff, P. Etienne, G. Creuzet, A. Friederich, and J. Chazelas, Physical Review Letters 61, 2472 (1988).
[2] G. Binasch, P. Grünberg, F. Saurenbach, and W. Zinn, Physical Review B 39, 4828 (1989).
[3] B. Dieny, V. S. Speriosu, S. S. P. Parkin, B. A. Gurney, D. R. Wilhoit, and D. Mauri, Physical Review B 43, 1297 (1991).
[4] C. Chappert, A. Fert, and F. N. Van Dau, Nat Mater 6, 813 (2007).
[5] M. Julliere, Physics Letters A 54, 225 (1975).
[6] S. Maekawa and U. Gafvert, Magnetics, IEEE Transactions on 18, 707 (1982).
[7] T. Miyazaki and N. Tezuka, Journal of Magnetism and Magnetic Materials 139, L231 (1995).
[8] J. S. Moodera, L. R. Kinder, T. M. Wong, and R. Meservey, Physical Review Letters 74, 3273 (1995).
[9] S. Yuasa, T. Nagahama, A. Fukushima, Y. Suzuki, and K. Ando, Nat Mater 3, 868 (2004).
[10] S. S. P. Parkin, C. Kaiser, A. Panchula, P. M. Rice, B. Hughes, M. Samant, and S.-H. Yang, Nat Mater 3, 862 (2004).
[11] M. A. Reed, C. Zhou, C. J. Muller, T. P. Burgin, and J.M. Tour. Conductance of molecular junction. Science 278, 252-254 (1997).
[12] M. Di Ventra, S. T. Pantelides, and N. D. Lang. First Principle Calculation of Transport Properties of a Molecule Device. Phys. Rev. Lett. 84,979 (2000)
[13] A.. R. Rocha, V. M. Garcia-Suarez, S. W. Bailey, C. J. Lambert, J. Ferrer, and S. Sanvito. Towards molecular spintronics. Nature Mater. 4, 335-339 (2005)
[14] S. Sanvito, Nat Phys 6, 562 (2010).
[15] D. Waldron, P. Haney, B. Larade, A. MacDonald, and H. Guo, Physical Review Letters 96, 166804 (2006).
[16] Z. Ning, Y. Zhu, J. Wang, and H. Guo, Physical Review Letters 100, 056803 (2008).
[17] B. Q. Xu, X. L. Li, X. Y. Xiao, H. Sakaguchi, and N. J. Tao, Nano Lett 5, 1491 (2005).
[18] Y. H. Tang, N. Kioussis, A. Kalitsov, W. H. Butler, and R. Car, Physical Review B 81, 054437 (2010).
[19] M. Born and R. Oppenheimer, Annalen der Physik 389, 457 (1927).
[20] Thomas L H. Proc. Cambridge Phil. Soc. , 1927 , 23 : 5422548.
[21] Fermi E Z. Phys. , 1928 , 48 : 73-79.
[22] Dirac P A M. Proc. Cambridge Phil. Soc. , 1930 , 26 : 3762385.
[23] P. Hohenberg and W. Kohn, Physical Review 136, B864 (1964).
[24] W. Kohn and L. J. Sham, Physical Review 140, A1133 (1965).
[25] L. Hedin and B. I. Lundqvist, J. Phys. C: Solid State Phys. 4, 2064 (1971).
[26] Ceperley D M , Alder B J . Phys. Rev. Lett . , 1980 , 45 (7) : 566-569.
[27] Perdew J P , Zunger A. Phys. Rev. B , 1981 , 23 (10) : 5048-5079.
[28] U. von Barth and L. Hedin, J. Phys. C: Solid State Phys. 5, 1629 (1972).
[29] Becke A D. Phys. Rev. A , 1988 , 38 ( 6 ) : 3098-3100.
[30] Lee C , Yang W , Parr R G. Phys. Rev. B , 1988 , 37 (2) : 785-789.
[31] Perdew J P. In : Ziesche P , Eschrig H. Editors. Electronic St ructure of Solids. Akademie Verlag , Berlin , 1991. Vol. 11.
[32] Perdew J P , Burke K, Ernzerhof M. Phys. Rev. Lett . 1996 , 77 (18) : 3865-3868.
[33] Hamann D R , Schl ′ uter M , Chiang C. Phys. Rev. Lett . 1979 , 43 (20) : 1494-1497.
[34] Bachelet G B , Hamann D R , Schl ′ uter M. Phys. Rev. B , 1982 , 26 (8) : 4199-4228.
[35] Vanderbilt D. Phys. Rev. B , 1990 , 41 ( 11 ) : 7892-7895.
[36] W. C. Herring, Phys. Rev. 57, 1169 (1940).
[37] W. C. Herring and A. G. Hill, Phys. Rev. 58: 132, 1940.
[38] Blochl P E. Phys. Rev. B , 1994 , 50 ( 24 ) : 17953-17979.
[39] Datta S. Elect ronic Transport in Mesoscopic System , England : Cambridge University Press , 1997.
[40] Taylor J . Ab-initio Modelling of Transport in Atomic Scale Devices , PhD thesis , Canada : McGill University , 2000.
[41] http://quantumwise.com/
[42] Computational aspects of electronic transport in nanoscale devices , Hans Henrik Brandenborg Sørensen , Kongens Lyngby 2008.
[43] J. Taylor, H. Guo, and J. Wang, Physical Review B 63, 245407 (2001).
[44] Sanvito S , Lambert C J , J efferson J H , et al. Phys.Rev. B , 1999 , 59 (18) : 11936211948 J. Taylor, H. Guo, J. Wang, Phys. Rev. B 63, 245407 (2001).
[45] Sancho M P L , Sancho J M L , Rubio J J . Phys. F : Met . Phys. , 1984 , 14 : 120521215.
[46] M. Brandbyge, J.-L. Mozos, P. Ordejón, J. Taylor, and K. Stokbro, Phys. Rev. B,65, 165401, 2002, 65, 165401.
[47] Quantum ESPRESSO, http://www.quantum-espresso.org/

指導教授

唐毓慧(Yu-Hui Tang)

審核日期

2016-1-11

推文