本文選題：量子反�；魻栃�(yīng)　切入點：n-p共摻雜　出處：《山西師范大學(xué)》2017年碩士論文

【摘要】：物理領(lǐng)域最基本,量子霍爾效應(yīng)是凝聚態(tài)最重要的量子效應(yīng)之一。在量子霍爾效應(yīng)中,強(qiáng)外磁場會產(chǎn)生朗道能級使得傳導(dǎo)的電子在體內(nèi)做忯旋導(dǎo)致體內(nèi)絕緣,邊界上的電子不能形成忯旋,使得電子在樣品邊上只能朝著一個方向傳輸形成了一個導(dǎo)電通道的邊界電流,由于該電流受體系拓?fù)湫缘谋Ｗo(hù),而不會受到缺陷的影響,因此可以應(yīng)用于設(shè)計無耗散或低耗散的電子學(xué)器件。但是,這種量子霍爾效應(yīng)需要極強(qiáng)的外磁場,這是實際器件設(shè)計的障礙之一。那么,有沒有不需要外加強(qiáng)磁場的量子霍爾效應(yīng)呢?這種不量子霍爾效應(yīng)需要施加強(qiáng)的外磁場的就是量子反�；魻栃�(yīng)。2013年我國科學(xué)家首次在實驗上成功地觀測到了這種現(xiàn)象,但是其觀測的溫度特別低,只有30m K,這就限制了它在低能耗電子學(xué)領(lǐng)域的潛在應(yīng)用。因此,提高量子反�；魻栃�(yīng)的觀測溫度,特別是在制備簡單的材料中實現(xiàn)高溫量子反�；魻栃�(yīng)就成為了目前急待解決的問題。自從石墨烯,硅烯被發(fā)現(xiàn)以來,一直被認(rèn)為是自旋電子學(xué)材料領(lǐng)域理想的材料。這些物質(zhì)的晶格結(jié)構(gòu)與1988年美國物理學(xué)家Haldane所描述的六角蜂窩結(jié)構(gòu)是完全一樣的。其能帶結(jié)構(gòu)具有線性的狄拉克色散關(guān)系,弱的自旋軌道耦合作用。理論和實驗研究表明加強(qiáng)這些二維材料的SOC即自旋軌道耦合有著至關(guān)重要的影響。因為許多奇異的物理現(xiàn)象與之息息相關(guān),比如自旋霍爾效應(yīng)。目前研究表明,在石墨烯,硅烯上吸附過渡金屬能夠顯著的增強(qiáng)它的外稟的自旋軌道耦合作用,進(jìn)而打開拓?fù)浞瞧接沟膸秮韺崿F(xiàn)量子反常霍爾效應(yīng)。但是通過單吸附過渡金屬來實現(xiàn)量子反�；魻栃�(yīng)的方式存在一些問題,如吸附穩(wěn)定性等。在這篇論文中,我們主要是基于過渡金屬原子能夠明顯增強(qiáng)石墨烯,硅烯的自旋軌道耦合作用,利用n-p共摻雜思想和第一性原理的計算方法,研究了以下兩方面的內(nèi)容:1.首先,我們系統(tǒng)的研究了八種5d過渡金屬原子單摻和共摻硼(B)吸附在石墨烯上的穩(wěn)定情況,接著計算了上述幾種原子共摻硼(B)后體系的電子結(jié)構(gòu),能帶圖顯示硼(B)/鉿(Hf)共摻雜石墨烯體系能夠產(chǎn)生拓?fù)浞瞧接沟牡谝环N類型的帶隙,大小為20.5me V。此外,在分析能帶圖的時候我們發(fā)現(xiàn)硼(B)/錸(Re)和硼(B)/鉑(Pt)共摻雜石墨烯這兩個體系有非常明顯的自旋劈裂現(xiàn)象,我們對其中的四條能帶進(jìn)行了詳細(xì)分析,發(fā)現(xiàn)自旋劈裂能絕對值?(35)so?達(dá)到158meV,比報道的由于內(nèi)稟的自旋軌道耦合導(dǎo)致的自旋劈裂能大好幾個數(shù)量級,這個結(jié)果有利于設(shè)計新型的自旋電子學(xué)材料。我們的這個研究為將高溫量子反�；魻栃�(yīng)應(yīng)用于實際提供了新的解決途徑。2.我們研究了5d過渡金屬吸附在硅烯體系的穩(wěn)定性的情況和電子結(jié)構(gòu)。我們首先發(fā)現(xiàn)Os摻雜硅烯體系能夠打開第一種類型的拓?fù)浞瞧接沟膸?大小為13.5meV,因此,可能實現(xiàn)量子反�；魻栃�(yīng)的。同時我們給Os摻雜硅烯體系上施加了-3%到2%的應(yīng)力后發(fā)現(xiàn)這個體系仍然是可能實現(xiàn)量子反常霍爾效應(yīng)的,且可調(diào)控。我們的這個研究為高溫量子反常霍爾效應(yīng)應(yīng)用于實際提供了新的方案。
[Abstract]:In the field of basic physics, quantum Holzer effect is one of the most important quantum effects in condensed state. In the quantum Holzer effect, strong magnetic field will produce the Landau energy conduction electron spin Qi in vivo resulted in the insulation, not on the boundary of the formation of Qi electron spin, so that the electric in the sample edge only toward a a transmission direction forming a conductive channel boundary current, due to the current protection system topology, and is not affected by the influence of defects, so it can be applied in the design of non dissipative or dissipation electronic devices. However, the quantum Holzer effect to external magnetic field, which is one of the actual device design obstacles. So, there is no effect of quantum Holzer do not need to strengthen the field? The quantum Holzer effect need applied to the external magnetic field is quantum anomalous Holzer effect.2013 Chinese scientists For the first time in the experiment successfully observed this phenomenon, but the observed temperature is very low, only 30m K, which limits its potential application in the field of electronics. Therefore, low energy consumption, improve the quantum anomalous Holzer effect observation of temperature, especially has become an urgent problem to realize high temperature anomalous quantum Holzer the effect in the preparation of simple materials. Since graphene, since silylenes was found, has been considered to be the ideal material field of spintronics materials. Six angle honeycomb structure lattice structure of these substances and the 1988 American physicist Haldane described is exactly the same. The Dirac dispersion relation can have a linear belt structure. Effect of spin orbit coupling is weak. Theoretical and experimental studies show that has important influence to strengthen these two-dimensional materials SOC spin orbit coupling. Because many strange things It is closely related with the physical phenomena, such as spin Holzer effect. The present study showed that in graphene, silylenes adsorbed on transition metal can enhance the effect of spin orbit coupling intrinsic it significantly, and then open the topological nontrivial gap to realize quantum anomalous Holzer effect. But there are some problems through the single transition metal adsorption to realize the quantum anomalous Holzer effect, such as adsorption stability. In this thesis, we mainly transition metal atoms can significantly enhance the graphene based on spin orbit coupling silylenes, calculation method of using N-P Co doped ideas and first principle, on the following two aspects: 1. first of all, we studied eight kinds of 5D transition metal atom doping boron (B) adsorption stability in graphene, the several atoms of boron doped (B) and then calculated after the electric system The sub structure, the band diagram shows the boron (B) / hafnium (Hf) Co doped graphene system can produce nontrivial topological band gap of the first type, the size of 20.5me V. in addition, when analyzing the energy band diagram we found that boron (B) / rhenium (Re) and boron (B) / platinum (Pt) Co doped graphene the two spin system has obvious splitting phenomenon, we can take a detailed analysis on the four, found that the spin splitting of absolute value? (35) so? Reached 158meV, than reported by splitting several orders of magnitude of spin in the spin orbit coupling intrinsic, this result is conducive to design spintronics materials. The model of our research for high temperature quantum anomalous Holzer effect applied to.2. provides a new solution we study 5D transition metal adsorption and electronic structure in the stability of silylenes system. We first discovered Os mixed Miscellaneous silylenes system can open the topology of the first type of non bandgap mediocrity, the size of 13.5meV, therefore, may realize the quantum anomalous Holzer effect. At the same time we give Os doped silicon ene system applied to -3% 2% stress after the discovery of this system is still possible to realize quantum anti Holzer effect and often. We can control. This research for high temperature quantum anomalous Holzer effect applied to provide a new solution.

【學(xué)位授予單位】：山西師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TB303

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 孫慶豐;;自旋軌道耦合和自旋流的研究若干進(jìn)展[J];物理;2008年08期

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本文編號：1707280