共查询到18条相似文献,搜索用时 62 毫秒
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利用两点Hubbard模型和Floquet定理,研究了交变电场驱动下耦合双量子点中激子的动力学行为.计算结果表明,系统准能级随交变电场振幅的变化出现一系列严格交叉和回避交叉.在最低的两个准能级的第一个严格交叉点处,初始局域状态一般能够保持,并且随着点内的电子空穴之间库仑相互作用的增强,动态局域化的程度会提高.在最低的两个准能级的第二和第三个严格交叉点处,随着交变电场的增强,这种动态局域化被破坏.在偏离准能严格交叉点和回避交叉点,则不能存在动态局域化现象.
关键词:
Floquet态
准能
局域态 相似文献
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经过激光辐照和高温退火加工能够生成多孔硅样品,在650—780 nm处检测到很强的光致荧光(PL)峰,并且有明显的钉扎和增强效应.实验表明,这种PL发光的强度与样品受辐照和退火的时间短密切相关.通过第一性原理模拟计算发现,样品表面用SiO 双键和Si—O—Si桥键钝化,能隙中会出现电子局域态.激光辐照和高温退火的时间长短决定了样品表面SiO双键和Si—O—Si桥键的密度,而该密度正是影响多孔硅量子点中电子局域态生成的关键.
关键词:
多孔硅量子点
硅氧钝化键
电子局域态 相似文献
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最近,电子态在量子阱垒上方的局域和束缚已为实验证实,这是电子的波动性和干波效应的一种直接实验证,试图介绍这种所谓“正能量”束缚态的形成机制,以引起我国学者注意。 相似文献
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HOU Bang-Pin WANG Shun-Jin WANG Gang SUN Wei-Li 《理论物理通讯》2007,48(2):232-242
When two identical QED cavities driven by the coherent fields are located in a uniform environment, in addition to dissipation, there appears an indirect coupling between the two cavities induced by the background fields. We investigate the effects of the coherent fields, the dissipation as well as the incoherent coupling on the following dynamical properties of the system: photon transfer, reversible decoherence, and quantum state transfer, etc. We find that the photons in the cavities do not leak completely into the environment due to the collective coupling between the cavities and the enviroment, and the photons are transferred irreversibly from the cavity with more photons to the cavity with less ones due to the incoherent coupling so that they are equally distributed among the two cavities. The coherent field pumping on the two cavities increases the mean photons, complements the revived magnitude of the reversible decoherence, but hinders the quantum state transfer between the two cavities. The above phenomena may find applications in quantum communication and other basic fields. 相似文献
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When two identical QED cavities driven by the coherent fields are located in a uniform environment, in addition to dissipation, there appears an indirect coupling between the two cavities induced by the background fields. We investigate the effects of the coherent fields, the dissipation as well as the incoherent coupling on the following dynamical properties of the system: photon transfer, reversible decoherence, and quantum state transfer, etc. We find that the photons in the cavities do not leak completely into the environment due to the collective coupling between the cavities and the enviroment, and the photons are transferred irreversibly from the cavity with more photons to the cavity with less ones due to the incoherent coupling so that they are equally distributed among the two cavities. The coherent field pumping on the two cavities increases the mean photons, complements the revived magnitude of the reversible decoherence, but hinders the quantum state transfer between the two cavities. The above phenomena may find applications in quantum communication and other basic fields. 相似文献
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The topic of improving the ability of quantum systems to retain non-local features and enhance the efficiency of quantum protocols continues. This study delves into the thermal investigation of quantum correlations and teleportation fidelity of a two-qubit teleported state using excess electrons in a coupled double quantum dots system as a quantum channel. The study employs three reliable quantum quantifiers to prospect the resourcefulness and non-classicality of the system. The findings suggest that preserving quantum correlations and optimizing teleportation fidelity require minimizing tunneling coupling and maximizing Coulomb interaction. The study has significant implications for quantum physics and its practical applications in quantum information processing. 相似文献
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Exciton energies as a function of radii of quantum dots in the range of 5-35 A are calculated based on effective mass approximation model with the B-spline technique and compared with experimental and other theoretical data for the CdS dots. This method leads to accurate and fast convergent exciton energy, which are in good agreement with experimental data in the whole confinement regime. The effect of penetration of wave function from the inside to the outside of the dots and the effect of dielectric constants are taken into account. The magnitudes of dynamical parameters are discussed. It is found that the different materials surrounding the CdS quantum dot affect not only the potential energy and Coulomb interaction energy of the system, but also the effective masses. The comparison shows that the effective mass approximation model can describe very well the quantum size effects observed experimentally on the exciton ground state energy. 相似文献
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YIN Miao CHENG Ze SHEN Lei-Lei 《理论物理通讯》2008,50(9):661-663
We investigate the generation of entanglement of coherent excitonic states in coupled quantum dots placed in a cavity by meaning of the state preparation fidelity [Nature (London) 404 (2002) 256; Phys. Rev. A 65 (2002) 012107; J. Uffink, Phys. Rev. Lett. 88 (2002) 230406.] The effect of the number of excitons and the coherent intensity |α| of the cavity field on the entanglement is also studied. 相似文献