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完整後設資料紀錄
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.advisor | 張慶瑞 | |
dc.contributor.author | Rui-An Chang | en |
dc.contributor.author | 張睿安 | zh_TW |
dc.date.accessioned | 2021-06-17T07:26:24Z | - |
dc.date.available | 2022-07-10 | |
dc.date.copyright | 2019-07-10 | |
dc.date.issued | 2019 | |
dc.date.submitted | 2019-06-26 | |
dc.identifier.citation | [1] Jackiw, R. & Rebbi, C. Solitons with fermion number 1/2. Phys. Rev. D 13, 33983409 (1976).
[2] Haldane, F. D. M. Model for a quantum Hall effect without landau levels: Condensedmatter realization of the ”parity anomaly”. Phys. Rev. Lett. 61, 2015-2018 (1988). [3] Hasan, M. Z. & Kane, C. L. Colloquium: Topological insulators. Rev. Mod. Phys. 82, 3045-3067 (2010). [4] Qi, X.-L. & Zhang, S.-C. Topological insulators and superconductors. Rev. Mod.Phys. 83, 1057-1110 (2011). [5] Majorana, E. Teoria simmetrica dell’elettrone e del positrone. Nuovo Cimento 14, 171 (1937). [6] Yu, R. et al. Quantized anomalous Hall effect in magnetic topological insulators. Science 329, 61-64 (2010). [7] Chang, C.-Z. et al. Experimental observation of the quantum anomalous Hall effect in a magnetic topological insulator. Science 340, 167-170 (2013). [8] Kou, X. et al. Metal-to-insulator switching in quantum anomalous Hall states. Nature Communications 6, 8474 (2015). [9] Qi, X.-L., Wu, Y.-S. & Zhang, S.-C. Topological quantization of the spin Hall effect in two-dimensional paramagnetic semiconductors. Phys. Rev. B 74, 085308 (2006). [10] Bernevig, B. A., Hughes, T. L. & Zhang, S.-C. Quantum spin Hall effect and topological phase transition in HgTe quantum wells. Science 314, 1757-1761 (2006). [11] Liu, C.-X., Zhang, S.-C. & Qi, X.-L. The quantum anomalous Hall effect: Theory and experiment. Annu. Rev. Condens. Matter Phys. 7, 301-321 (2016). [12] Asb´oth, J. K., Oroszl´any, L. & P´alyi, A. A Short Course on Topological Insulators Ch.6 (Springer International Publishing, Switzerland, 2016). [13] Matsukura, F., Tokura, Y. & Ohno, H. Control of magnetism by electric fields. Nature Nanotechnology 10, 209-220 (2015). [14] Hanke, J.-P., Freimuth, F., Niu, C., Bl¨ugel, S. & Mokrousov, Y. Mixed Weyl semimetals and low-dissipation magnetization control in insulators by spin–orbit torques. Nature Communications 8, 1479 (2017). [15] Xiao, D., Chang, M.-C. & Niu, Q. Berry phase effects on electronic properties. Rev. Mod. Phys. 82, 1959-2007 (2010). [16] Zhang, Y. & Das Sarma, S. Spin Polarization Dependence of Carrier Effective Mass in Semiconductor Structures: Spintronic Effective Mass. Phys. Rev. Lett. 95, 256603 (2005). [17] Datta, S. Electronic Transport in Mesoscopic Systems (Cambridge University Press, Cambridge, 1997). [18] Datta, S. Quantum Transport: Atom to Transistor (Cambridge University Press, Cambridge, 2005). [19] Winkler, R. Spin-orbit Coupling Effects in Two-Dimensional Electron and Hole Systems (Springer, Berlin, 2003) [20] Thouless, D. J., Kohmoto, M., Nightingale, M. P. & den Nijs, M. Quantized Hall conductance in a two-dimensional periodic potential. Phys. Rev. Lett. 49, 405-408 (1982). [21] Nikoli´c, B. K., Zˆarbo, L. P. & Souma, S. Imaging mesoscopic spin Hall flow: Spatial distribution of local spin currents and spin densities in and out of multiterminal spinorbit coupled semiconductor nanostructures. Phys. Rev. B 73, 075303 (2006). [22] Mahfouzi, F., Nagaosa, N. & Nikoli´c, B. K. Spin-to-charge conversion in lateral and vertical topological-insulator/ferromagnet heterostructures with microwave-driven precessing magnetization. Phys. Rev. B 90, 115432 (2014). [23] Mahfouzi, F., Nikoli´c, B. K., Chen, S.-H. & Chang, C.-R. Microwave-driven ferromagnet–topological-insulator heterostructures: The prospect for giant spin battery effect and quantized charge pump devices. Phys. Rev. B 82, 195440 (2010). [24] Lindner, N.H., Refael, G. & Galitski, V. Floquet topological insulator in semiconductor quantum wells. Nat. Phys. 7, 490-495 (2011). [25] D’Alessio, L. & Rigol, M. Dynamical preparation of Floquet Chern insulators. Nature Communications 6, 8336 (2015). [26] Chaudhary, S., Endres, M. & Refael, G. Berry electrodynamics: Anomalous drift and pumping from a time-dependent Berry connection. Phys. Rev. B 98, 064310 (2018). [27] Slonczewski, J. S. Current-driven excitation of magnetic multilayers. Journal of Magnetism and Magnetic Materials 159, L1-L7 (1996). [28] Qi, X.-L., Hughes, T. L. & Zhang, S.-C. Chiral topological superconductor from the quantum Hall state. Phys. Rev. B 82, 184516 (2010). [29] Chen, S.-H. & Chang, C.-R. Non-Abelian spin-orbit gauge: Persistent spin helix and quantum square ring. Phys. Rev. B 77, 045324 (2008). [30] Tserkovnyak, Y. & Loss, D. Thin-film magnetization dynamics on the surface of a topological insulator. Phys. Rev. Lett. 108, 187201 (2012). [31] Zarezad, A. N. & Abouie, J. Transport in magnetically doped topological insulators: Effects of magnetic clusters. Phys. Rev. B 98, 155413 (2018). [32] Wang, J., Lian, B. & Zhang, S.-C. Dynamical axion field in a magnetic topological insulator superlattice. Phys. Rev. B 93, 045115 (2016). [33] Tran, M.-T., Nguyen, H.-S. & Le, D.-A. Emergence of magnetic topological states in topological insulators doped with magnetic impurities. Phys. Rev. B 93, 155160 (2016). [34] Chiu, C.-K., Teo, J. C. Y., Schnyder, A. P. & Ryu, S. Classification of topological quantum matter with symmetries. Rev. Mod. Phys. 88, 035005 (2016). [35] Nayak, C., Simon, S. H., Stern, A., Freedman, M. & Das Sarma, S. Non-Abelian anyons and topological quantum computation. Rev. Mod. Phys. 80, 1083-1159 (2008). | |
dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/73284 | - |
dc.description.abstract | 一直以來,在陳絕緣體中被高度討論的拓撲相變大部分是藉由調整內在的材料參數所引發的,例如:交換耦合的強度。但在真實的應用當中,這並不是一個引發拓撲相變的實際方法。在此,我們表明拓撲相變可藉由調整以二維電子氣所形成的陳絕緣體之外在自由度-磁化方向來引發,其中二維電子氣具有Dresselhaus [001]自旋軌道耦合,且與其上方之磁性層有著交換耦合。透過解析的方法,我們表明該系統在面內磁化的情形下有著拓撲平庸的相,但當磁化偏離面內方向時則會發生拓撲相變。此解析的結果已進一步地利用非平衡態格林函數驗證。若將以上的拓撲相變和自旋轉移力矩結合,我們可以基於這種拓撲學和自旋電子學的前瞻性融合,設計出一種新穎的電晶體。最後我們將以上討論的陳絕緣體加上了s波超導體,形成了手性拓撲超導體。這種材料在拓撲量子計算上會有很重要的應用。 | zh_TW |
dc.description.abstract | So far, the highly-discussed topological phase transitions in Chern insulators have mostly been induced by tuning an intrinsic material parameter such as the exchange coupling strength. But it is not a practical way to induce topological phase transitions in real applications. Here we show that the topological phase transitions can be induced by tuning the extrinsic degree of freedom, magnetization orientation, in a Chern insulaotr formed by a two-dimensional electron gas with Dresselhaus [001] spin-orbit coupling and an exchange coupling to a ferromagnetic overlayer. In an analytic way, we show that this system has a topologically trivial phase with in-plane magnetization but undergoes a topological phase transition when the magnetization is deviated from the in-plane direction. The analytic results are further confirmed by numerical nonequilibrium Green functions calculations. With the combination of this phase transition and spin-transfer torque, a novel transistor can be designed with this promising fusion of topology and spintronics. At last, we combine this Chern insulator with an s-wave superconductor, forming the chiral topological superconductor. It will have vital applications in topological quantum computation. | en |
dc.description.provenance | Made available in DSpace on 2021-06-17T07:26:24Z (GMT). No. of bitstreams: 1 ntu-108-R05245001-1.pdf: 6756701 bytes, checksum: cf8932bc4b5d24998f62009ca5416fd4 (MD5) Previous issue date: 2019 | en |
dc.description.tableofcontents | 誌謝 i
摘要 ii Abstract iii 1 Introduction 1 1.1 Integer Quantum Hall Effect . . . . . . . . . . . . . . . . . . . . . . . .1 1.2 Quantum Anomalous Hall Effect . . . . . . . . . . . . . . . . . . . . . .3 1.3 Motivation and Outline . . . . . . . . . . . . . . . . . . . . . . . . . . .4 2 Theoretical Background 6 2.1 From Berry Phase to Chern Number . . . . . . . . . . . . . . . . . . . .6 2.1.1 Berry Phase, Berry Connection, and Berry Curvature . . . . . . .6 2.1.2 Chern Number . . . . . . . . . . . . . . . . . . . . . . . . . . .8 2.1.3 Chern Number for Two-band Systems . . . . . . . . . . . . . . .9 2.2 Qi-Wu-Zhang Model . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 2.3 Tight-binding Model . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 2.4 Interpretation of QWZ Model . . . . . . . . . . . . . . . . . . . . . . . .16 3 Nonequilibrium Green Functions 18 3.1 Green functions in quantum mechanics . . . . . . . . . . . . . . . . . . .18 3.2 Adding leads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 3.3 Landauer-Keldysh formalism . . . . . . . . . . . . . . . . . . . . . . . .20 3.4 Landauer-Buttiker formula . . . . . . . . . . . . . . . . . . . . . . . . .21 4 Results 22 4.1 Model and topological invariant . . . . . . . . . . . . . . . . . . . . . .22 4.2 Topological phase transitions . . . . . . . . . . . . . . . . . . . . . . . .25 4.3 Numerical results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 4.4 Azimuthal degree of freedom and novel transistor . . . . . . . . . . . . .33 4.5 Line defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 4.6 An extension to chiral topological superconductors . . . . . . . . . . . .36 4.7 Summary and outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Bibliography 38 | |
dc.language.iso | en | |
dc.title | 在陳絕緣體中由可變之磁化方向所引發的拓撲相變 | zh_TW |
dc.title | Topological Phase Transitions in Chern Insulators with Tunable Magnetization Orientations | en |
dc.type | Thesis | |
dc.date.schoolyear | 107-2 | |
dc.description.degree | 碩士 | |
dc.contributor.oralexamcommittee | 管希聖,張明哲 | |
dc.subject.keyword | 量子反常霍爾效應,陳絕緣體,祁-吳-張 模型,拓撲相變,非平衡態格林函數,拓撲超導體, | zh_TW |
dc.subject.keyword | Quantum anomalous Hall effect,Chern insulator,Qi-Wu-Zhang model,Topological phase transition,Nonequilibrium Green functions,Topological superconductor, | en |
dc.relation.page | 41 | |
dc.identifier.doi | 10.6342/NTU201901054 | |
dc.rights.note | 有償授權 | |
dc.date.accepted | 2019-06-27 | |
dc.contributor.author-college | 理學院 | zh_TW |
dc.contributor.author-dept | 應用物理研究所 | zh_TW |
顯示於系所單位: | 應用物理研究所 |
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