物質的超導態具有完全的零電阻以及抗磁性而在工程上有重要的應用，近幾年的實驗中發現了原本理論預測的新穎超導態-拓樸超導-而使這個領域更熱絡的發展。拓樸超導具有拓樸的性質，可以保護材料中一些重要的資訊不被破壞，這個重要的特性剛好可以應用在量子電腦上，量子電腦的基礎材料-量子位元-非常容易受到外在環境影響，而拓樸超導體形成的一對馬約拉納費米子可以被拓樸態保護，使得資訊不會消失。

我的實驗是將錳作為磁性的雜質鍍在鉛在矽上所形成的薄膜上，鉛在矽上形成的薄膜具有超導性，而在傳統超導上鍍上磁性雜質理論上有可能會形成拓樸超導。STM是觀察這個拓樸超導最好的工具之一，因此我的實驗主要是觀察鉛和錳鍍在矽上的表面型態以及探討成膜的機制。

The superconducting state of a material has totally zero resistance and magnetic resistance, so it has important application in engineering. In recent years' experiments, a new superconducting state predict by theorem (topological superconductivity) was be founded and caused this field to even flourish. Topological superconductivity has the property of topology. It can protect some important information in material and this property can be used in quantum computer.The fundamental material of quantum computer, qubit, affected by the surrounding easily, and a pair of Majorana fermions formed by topological superconductor can be protected by topological state. So the information will not disappear.

My experiment is to deposit Mn as the magnetic impurities on the thin film of Pb on Si. The thin film of Pb on Si has superconductivity, and in theorem that deposit magnetic impurity on traditional superconductor may form topological superconductor. STM is one of the best tools to measure this topological superconductor. So my experiment will mainly focus on the surface topography and growth behavior of Mn and Pb depositing on Si.

[1] Azatyan et al.. Variable termination of MnSi/Si(111) √3x√3 films and its effect on surface properties. Surf. Sci. 605, 289-295 (2011).
[2] Menard, Gerbold et al.. Two-dimensional topological superconductivity in Pb/Co/Si(111). Nat. Commun. 8, 2040 (2016).
[3] 陳筠婷. 二鍗化鈦與二硒化鈦於雙層石墨烯上的橫向應變異質接面. MA thesis (清華大學物理所, 2018).
[4] N Nicoara et al.. Growth of ordered molecular layers of PTCDA
on Pb/Si(111) surfaces: a scanning tunneling microscopy study.
Nanotechnology 27, 365706 (2016).
[5] R. Shankar. Topological Insulators { A review. arXiv:1804.06471 (2016).
[6] Masatoshi Sato et al.. Topological superconductors: a review.
arXiv:1608.03395 (2016).
[7] Brihuega, Ivan. Surface diusion of Pb single adatoms on the
Si (111)-(√3x√3) R30°- Pb system. Phys. Rev. B 76, 035422
(2007).
[8] 丁南宏. 真空技術與應用(全華出版社, 2009).
[9] Grytzelius, Joakim et al.. Coverage dependence and surface
atomic structure of Mn/Si(111)-3×3 studied by scanning tunneling
microscopy and spectroscopy. Phys. Rev. B 80, 235324
(2009).
[10] Principles of lock-in detection and the state of the
art. https://www.zhinst.com/others/resources/principles-lockdetection
[11] Miniature Knudsen Evaporation Cell.
https://www.chell.co.uk/vacuum/miniature-knudsenevaporation-
cell/miniature-knudsen-evaporation-cell/k-cellminiature-
knudsen-evaporation-cell
[12] Alcatel Drytel 1025 Pumping Unit User's Manual.
https://www.yumpu.com/en/document/view/5875577/alcateladixen-
pfeier-drytel-1025-users-service-instruction-
[13] Varian TSP (916-0017) Manual.
https://www.idealvac.com/Agilent-Varian-Titanium-
Sublimation-Pump-(TSP)-Controller/pp/P105257
[14] Varian Turbo V70LP Pumps User's Manual.
https://www.manualslib.com/manual/1189294/Varian-Turbo-
V70lp.html
[15] Tresca, C. et al.. Chiral Spin Texture in the Charge-Density-
Wave Phase of the Correlated Metallic Pb/Si(111) Monolayer.
Phys. Rev. Lett. 120, 196402 (2018).
[16] Wang, Jun-Zhong et al.. Spontaneous formation of Mn nanocluster arrays on a Si(111)-7x7 surface observed with STM.
Phys. Rev. B 78, 045424 (2008).
[17] Brihuega, I. et al.. Defects in the (√3x√3)↔(3x3) phase
transition in the PbSi(111) system. Phys. Rev. B 75, 155411
(2007).
[18] 莊天明. 拓樸超導體(物理雙月刊, 2017).
[19] Zhang, Tong et al.. Superconductivity in one-atomic-layer metal films grown on Si(111). Nat. Phys. 6, 104-108 (2010).
[20] How can a mug and a torus be equivalent if the mug is chiral?
https://math.stackexchange.com/questions/2258389/howcan-
a-mug-and-a-torus-be-equivalent-if-the-mug-is-chiral
[21] Vazquez de Parga, Amadeo L. Scanning Tunneling Spectroscopy.
(Springer Netherlands, 2012)
[22] Lin, JIa-Ling et al.. Formation of regular step arrays on
Si(111)7×7. J. Appl. Phys. 84, 255-260 (1998).
[23] Kim, Jungdae et al.. Universal quenching of the superconducting state of two-dimensional nanosize Pb-island structures. Phys. Rev. B 84, 014517 (2011).
[24] Hupalo, Myron et al.. "Devil's Staircase" in Pb/Si(111) Ordered Phases. Phys. Rev. Lett. 90, 216106 (2003).
[25] Zhi-Qiang Zou et al.. Two-dimensional fractal-like growth
on semiconductors: The formation of continuous manganese
monosilicide ultrathin films on Si(111). Phys. Lett. A 375, 849-
854 (2011).
[26] Geisler, Benjamin et al.. Strain stabilization and thickness dependence of magnetism in epitaxial transition metal monosilicide
thin lms on Si(111). Phys. Rev. B 88, 115433 (2013).
[27] S. Eilers et al.. Pb thin films on Si(111): Local density of states and defects. (2014).
[28] Shih, Chih-Kang. Superconductivity at the Two-dimensional
Limit. Science 324,1314-1317 (2010).
[29] Stepniak-Dybala, Agnieszka et al.. Silicene Nanoribbons on Pb-Reconstructed Si(111) Surface y. Condens. Matter 1, 8 (2016).
[30] 劉柏佑. Growth and Electronic Structures of 2D Pb Nanoislands
on Nb-Doped SrTiO3(001). MA thesis (清華大學物理所, 2020)
[31] 陳易苙. 反鐵磁鉻探針的製備和應用. MA thesis (清華大學物理所, 2019)
[32] John S. Townsend. A Modern Approach to Quantum Mechanics.
(University Science Books, 2012)
[33] Neil W. Ashcroft et al.. Solid State Physics. (CENGAGE, 2017)
[34] Charles Kittel. Introduction to Solid State Physics. (WILEY,
2005)
[35] R. Shankar. Principles of Quantum Mechanics. (Plenum Press,
1994)
[36] Pin-Jui Hsu. Growth of ordered molecular layers of PTCDA
on Pb/Si(111) surfaces: a scanning tunneling microscopy study
Nanotechnology 27, 365706 (2016).
[37] Mary L. Boas. Mathematical Methods in the Physical Sciences.
(WILEY, 2006)
[38] Higashi, Shougo et al.. Reactive epitaxial growth of MnSi ultrathin films on Si(111) by Mn deposition. Phys. Rev. B 79,
205312 (2009).
[39] Eric Ganz et al.. Growth and morphology of Pb on Si(111). Surf. Sci. 257, 259-273 (1991).
[40] T. Suzuki et al.. Surface morphology of MnSi thin films grown
on Si(111). Surf. Sci. 617, 106-112 (2013).
[41] Hupalo, M. et al.. SAtomic models, domain-wall arrangement,
and electronic structure of the dense Pb/Si(111)-√3x√3 phase. Phys. Rev. B 66, 161410 (2002).
[42] Kahwaji, Samer et al.. Surfactant-mediated growth of ferromagnetic Mn δ-doped Si. Phys. Rev. B 88, 174419 (2013).
[43] Horikoshi, Kotaro et al.. Structural phase transitions of Pb adsorbed Si(111) surfaces at low temperatures. Phys. Rev. B
60, 13287-13290 (1999).
[44] Eric Ganz et al.. Growth and morphology of Pb on Si(111). Surf. Sci. 257, 259-273 (1991).
[45] Chan, Tzu-Liang et al.. First-principles studies of structures and stabilities of Pb/Si(111). Phys. Rev. B 68, 045410 (2003).