QUANTUM DYNAMICS IN CONDENSED MATTER WITH STRONG NONADIABATIC PROCESSES

（1）芯激子X射线发射的非绝热过程我们从理论上研究了石墨芯激子的X射线发射谱。通过将电子振动团簇嵌入到导带的连续区中，不仅考虑了芯激发点的电子振动耦合，而且考虑了电子的巡游性，由于强的晶格弛豫，X射线发射谱具有较长的低能拖尾。对称性破缺的准Jahn-Teller相互作用产生了退极化的X射线辐射。随着晶格弛豫的进行，芯激子的性质由浅向深发生变化，称为动力学转变。计算的X射线吸收谱和X射线发射谱与实验数据符合得很好。（2）俄歇诱导脱附过程中双空穴态的时间演化我们阐明了双空穴-单原子系统中原子在俄歇诱导脱附过程中的量子动力学性质。 关于我们 矿洞在Knotek-Feibelman模型中，X射线诱导吸附原子的脱附是由于俄歇衰变后双空穴态的不稳定性。我们考虑了表面空穴的量子扩散效应，以及两个空穴之间的库仑相互作用。采用积分方程方法计算了两空穴一原子系统的高度非绝热量子动力学。结果表明，两空穴间的排斥作用使两空穴束缚态稳定，从而提高了脱附量子产率。（3）量子比特的非绝热控制我们提出了一种新的量子比特控制方法，利用重复Landau-Zener跃迁的相位关联效应来控制量子比特。通过调整交叉点之间的动力学相位，可以实现量子比特的任意幺正变换。此外，利用绝热通道的π脉冲可以抑制随机涨落引起的退相干。少

(1)Nonadiabatic Processes in Core Exciton X-Ray EmissionWe have investigated theoretically the X-ray emission spectrum of core excitons in graphite. By embedding the vibronic cluster in the continuum of the conduction band, we took into account not only the vibronic coupling at the core-excited site but also the itinerancy of the electron. Because of the strong lattice relaxation, the X-ray emission spectrum has a long low energy tail. The symmetry breaking quasi Jahn-Teller interaction gives rise to the depolarized X-ray emission. The character of the core exciton changes from shallow to deep as the lattice relaxation goes on, which is called the dynamical change-over. The calculated spectra of the X-ray absorption and the X-ray emission agree with the experimental date well.(2)Time-evolution of a Two-Hole State in Auger-Induced DesorptionWe have clarified the quantum dynamics of the two-hole-one-atom system in the atomic desorption from the surface induced by the Auger decay of the c … More ore hole. In the model of Knotek-Feibelman, the X-ray induced desorption of an adatom is due to the instability of the two-hole state after the Auger decay. We take into account the effect of the quantum diffusion of the holes in the surface, and the Cooulombic interaction between the two holes. The highly nonadiabatic quantum dynamics of the two-hole-one-atom system has been calculated by introducing the technique of intergral equation. It has been shown that the repulsive interaction between the two hole make the two-hole bound state stable, thus enhancing the quantum yield of desorption.(3)Nonadiabatic Control of QubitsWe have proposed a novel method of control of qubits by applying the phase correlation effect of the repeated Landau-Zener transitions. By adjusting the dynamical phase between the crossings, arbitrary unitary transformations of a qubit can be attained. Furthermore, the decoherence due to the stochastic fluctuation can be suppressed by taking advantage of the pi-pulse of the adiabatic passages. Less