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GaAs(111)表面硅烯、锗烯的几何及电子性质研究 被引量:2
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作者 张弦 郭志新 +2 位作者 曹觉先 肖思国 丁建文 《物理学报》 SCIE EI CAS CSCD 北大核心 2015年第18期57-64,共8页
基于密度泛函理论的第一性原理计算方法,系统研究了硅烯、锗烯在GaAs(111)表面的几何及电子结构.研究发现,硅烯、锗烯均可在As-中断和Ga-中断的GaAs(111)表面稳定存在,并呈现蜂窝状六角几何构型.形成能计算结果证明了其实验制备的可行性... 基于密度泛函理论的第一性原理计算方法,系统研究了硅烯、锗烯在GaAs(111)表面的几何及电子结构.研究发现,硅烯、锗烯均可在As-中断和Ga-中断的GaAs(111)表面稳定存在,并呈现蜂窝状六角几何构型.形成能计算结果证明了其实验制备的可行性.同时发现硅烯、锗烯与GaAs表面存在共价键作用,这破坏了其Dirac电子性质.进一步探索了利用氢插层恢复硅烯、锗烯Dirac电子性质的方法.发现该方法可使As-中断面上硅烯、锗烯的Dirac电子性质得到很好恢复,而在Ga-中断面上的效果不够理想.此外,基于原子轨道成键和杂化理论揭示了GaAs表面硅烯、锗烯能带变化的物理机理.研究结果为硅烯、锗烯在半导体基底上的制备及应用奠定了理论基础. 展开更多
关键词 硅烯 锗烯 dirac电子 GAAS表面
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锗烯在金属衬底上的结构及电子性质的第一性原理研究 被引量:1
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作者 佘彦超 罗开武 李勇 《原子与分子物理学报》 CAS 北大核心 2018年第5期861-866,共6页
基于密度泛函理论的第一性原理计算,我们系统的研究了锗烯在Pt(111)、Au(111)和Al(111)表面的几何和电子结构.在这三种金属衬底上寻找到了9种结构,其中Al(111)-a、Au(111)-b和Pt(111)-c结构就是目前实验上已经成功制备的结构.我们还发... 基于密度泛函理论的第一性原理计算,我们系统的研究了锗烯在Pt(111)、Au(111)和Al(111)表面的几何和电子结构.在这三种金属衬底上寻找到了9种结构,其中Al(111)-a、Au(111)-b和Pt(111)-c结构就是目前实验上已经成功制备的结构.我们还发现了其余6种目前理论和实验均没有提出,此外,Al(111)-b、Au(111)-a和Pt(111)-b结构的Dirac态仍保留,这些结构的形成能均大于范德瓦尔斯作用,因此非常有希望在实验上制备出来,应用于量子自旋霍尔效应的研究.本文的研究为锗烯在半导体衬底上的制备及应用奠定了理论基础. 展开更多
关键词 锗烯 金属衬底 dirac电子 第一性原理
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光子辅助Fano共振隧穿周期双阱势特性 被引量:2
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作者 张永棠 《中国光学》 EI CAS CSCD 北大核心 2021年第5期1251-1258,共8页
周期双阱势的光学性质是激光物理和量子光学的前沿研究领域之一。该文研究了具有时间周期双阱势的石墨烯系统中光子辅助狄拉克电子的Fano型共振隧穿。利用双量子阱结构,电子通过两量子阱之间的薄势垒的共振隧穿将导致束缚态能级的分裂,F... 周期双阱势的光学性质是激光物理和量子光学的前沿研究领域之一。该文研究了具有时间周期双阱势的石墨烯系统中光子辅助狄拉克电子的Fano型共振隧穿。利用双量子阱结构,电子通过两量子阱之间的薄势垒的共振隧穿将导致束缚态能级的分裂,Fano型共振谱将分裂为两个不对称共振峰。通过改变相位、频率和振幅来调制Fano峰的形状,可以用来调制Dirac在石墨烯中的电子输运性质。数值分析表明,两个振荡场的相对相位可以调节非对称Fano型共振峰的形状。当相对相位从0增加到π时,共振峰谷从峰的一侧移到另一侧;在临界相位3π/11处,不对称共振峰变得对称。此外,还可以通过改变振荡场的频率和振幅以及静态势阱的结构来调制Fano峰的分布。这些有趣的物理性质可以用来调节石墨烯中Dirac的电子输运性质。 展开更多
关键词 物理光学 共振隧穿 光子辅助隧穿 狄拉克电子 量子光学
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E-Infinity Dualities, Discontinuous Spacetimes, Xonic Quantum Physics and the Decisive Experiment 被引量:2
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作者 Jean-Paul Auffray 《Journal of Modern Physics》 2014年第15期1427-1436,共10页
Using powerful concepts and tools borrowed from the seminal arsenal connecting physics fundamentals with esoteric set theoretical operations developed in recent years by Alexandria E-infinity theoretician M. S. El Nas... Using powerful concepts and tools borrowed from the seminal arsenal connecting physics fundamentals with esoteric set theoretical operations developed in recent years by Alexandria E-infinity theoretician M. S. El Naschie, this paper explores the deep implications of some of the dualities Dr El Naschie has identified and analyzed in his exposes, connecting them with our own Xonic Quantum Physics (XQP) which places dynamical action rather than spacetime and energy at the core of the System of the World. 展开更多
关键词 E-INFINITY El Naschie Space Time SPACETIME Topology CANTOR Sets Energy Xon Xonic Quantum Physics PLANCK Scale dirac electron
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Spin-Magnetic Moment of Dirac Electron, and Role of Zitterbewegung
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作者 Shigeru Sasabe 《Journal of Modern Physics》 2014年第7期534-542,共9页
The spin-magnetic moment of the electron is revisited. In the form of the relativistic quantum mechanics, we calculate the magnetic moment of Dirac electron with no orbital angular-momentum. It is inferred that obtain... The spin-magnetic moment of the electron is revisited. In the form of the relativistic quantum mechanics, we calculate the magnetic moment of Dirac electron with no orbital angular-momentum. It is inferred that obtained magnetic moment may be the spin-magnetic moment, because it is never due to orbital motion. A transition current flowing from a positive energy state to a negative energy state in Dirac Sea is found. Application to the band structure of semiconductor is suggested. 展开更多
关键词 Spin-Magnetic Moment ZITTERBEWEGUNG G-FACTOR dirac electron Band Structure Semiconductor
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无序对准一维矢势束缚中无质量Dirac电子的影响
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作者 宋世英 高先龙 《浙江师范大学学报(自然科学版)》 CAS 2013年第1期68-73,共6页
通过有限差分的方法,数值计算了一个相对论性质的Dirac电子在磁场和无序同时存在时的能谱结构,并讨论了不同磁场强度和无序强度时电子密度分布的变化情况.结果发现:随着无序强度的增大,无序势削弱了磁场对电子的捕获,使局域化现象减弱,... 通过有限差分的方法,数值计算了一个相对论性质的Dirac电子在磁场和无序同时存在时的能谱结构,并讨论了不同磁场强度和无序强度时电子密度分布的变化情况.结果发现:随着无序强度的增大,无序势削弱了磁场对电子的捕获,使局域化现象减弱,使得无质量Dirac电子出现了有别于Anderson局域化的现象. 展开更多
关键词 无序 一维 dirac电子 电子密度分布
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二维无质量狄拉克电子朗道能级的解析处理 被引量:3
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作者 王大理 《大学物理》 北大核心 2013年第9期15-17,共3页
从量子力学的基本概念出发,在朗道规范和对称规范两种规范变换下,借助特殊函数方程理论,推导出单层石墨中二维无质量狄拉克电子朗道能级的解析表达式,并讨论它与通常二维电子气中薛定谔型电子的朗道能谱间存在的差异.
关键词 单层石墨 二维狄拉克电子 朗道能级
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A Physical Insight into the Origin of the Corrections to the Magnetic Moment of Free and Bound Electron
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作者 Nicolae Bogdan Mandache 《Journal of Modern Physics》 2020年第9期1301-1311,共11页
The main goal of the present work is a unitary approach of the physical origin of the corrections to the magnetic moment of free and bound electron. Based on this approach, estimations of lowest order corrections were... The main goal of the present work is a unitary approach of the physical origin of the corrections to the magnetic moment of free and bound electron. Based on this approach, estimations of lowest order corrections were easily obtained. In the non-relativistic limit, the Dirac electron appears as a distribution of charge and current extended over a region of linear dimension of the order of Compton wavelength, which generates its magnetic moment. The e.m. mass (self-energy) of electron outside this region does not participate to this internal dynamics, and consequently does not contribute to the mass term in the formula of the magnetic moment. This is the physical origin of the small increase of the magnetic moment of free electron compared to the value given by Dirac equation. We give arguments that this physical interpretation is self-consistent with the QED approach. The bound electron being localized, it has kinetic energy which means a mass increase from a relativistic point of view, which determines a magnetic moment decrease (relativistic Breit correction). On the other hand, the e.m. mass of electron decreases at the formation of the bound state due to coulomb interaction with the nucleus. We estimated this e.m. mass decrease of bound electron only in its internal dynamics region, and from it the corresponding increase of the magnetic moment (QED correction). The corrections to the mass value are at the origin of the lowest order corrections to the magnetic moment of free and bound electron. 展开更多
关键词 Magnetic Moment of dirac electron Electromagnetic Self-Energy Physical Origin of the Corrections to the Magnetic Moment of Free and Bound electron
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Ferromagnetic-insulators-modulated transport properties on the surface of a topological insulator
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作者 郭俊吉 廖文虎 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第6期484-488,共5页
Transport properties on the surface of a topological insulator (TI) under the modulation of a two-dimensional (2D) ferromagnet/ferromagnet junction are investigated by the method of wave function matching. The sin... Transport properties on the surface of a topological insulator (TI) under the modulation of a two-dimensional (2D) ferromagnet/ferromagnet junction are investigated by the method of wave function matching. The single ferromagnetic barrier modulated transmission probability is expected to be a periodic function of the polarization angle and the planar rotation angle, that decreases with the strength of the magnetic proximity exchange increasing. However, the transmission probability for the double ferromagnetic insulators modulated n-n junction and n-p junction is not a periodic function of polarization angle nor planar rotation angle, owing to the combined effects of the double ferromagnetic insulators and the barrier potential. Since the energy gap between the conduction band and the valence band is narrowed and widened respectively in ranges of 0 ≤ 0 〈π/2 and r/2 〈 0 ≤ π, the transmission probability of the n-n junction first increases rapidly and then decreases slowly with the increase of the magnetic proximity exchange strength. While the transmission probability for the n-p junction demonstrates an opposite trend on the strength of the magnetic proximity exchange because the band gaps contrarily vary. The obtained results may lead to the possible realization of a magnetic/electric switch based on TIs and be useful in further understanding the surface states of TIs. 展开更多
关键词 transport properties surface state dirac electron topological insulator ferromagnetic insulators
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Microscopic calculation of the magnetic field of neutron stars
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作者 刘军 贾文志 王顺金 《Chinese Physics C》 SCIE CAS CSCD 2009年第9期737-742,共6页
Based on the Dirac equation describing an electron moving in a uniform and cylindrically symmetric magnetic field which may be the result of the self-consistent mean field of the electrons themselves in a neutron star... Based on the Dirac equation describing an electron moving in a uniform and cylindrically symmetric magnetic field which may be the result of the self-consistent mean field of the electrons themselves in a neutron star, we have obtained the eigen solutions and the orbital magnetic moments of electrons in which each eigen orbital can be calculated. From the eigen energy spectrum we find that the lowest energy level is the highly degenerate orbitals with the quantum numbers pz = 0, n = 0, and m ≥0. At the ground state, the electrons fill the lowest eigen states to form many Landau magnetic cells and each cell is a circular disk with the radius λfree and the thickness λe, where λfree is the electron mean free path determined by Coulomb cross section and electron density and λe is the electron Compton wavelength. The magnetic moment of each cell and the number of cells in the neutron star are calculated, from which the total magnetic moment and magnetic field of the neutron star can be calculated. The results are compared with the observational data and the agreement is reasonable. 展开更多
关键词 microscopic calculation of magnetic field of neutron stars dirac equation of electrons in a uniform magnetic mean field orbital magnetic moment and Landau magnetic cell
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