Extended Peierls-Hubbard Model for One-Dimensional N-Sites N-Electrons System. III. Lattice Relaxation after Optical Excitation in CDW
Extended Peierls-Hubbard Model for One-Dimensional N-Sites N-Electrons System. III. Lattice Relaxation after Optical Excitation in CDW
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一维 N 位 N 电子系统的扩展 Peierls-Hubbard 模型。
DOI：
10.1143/jpsj.53.427
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发表时间：
1984
影响因子：
1.7
通讯作者：
K. Nasu
中科院分区：
文献类型：
--
作者：
K. Nasu
本文用激子变分法和声子绝热极限法研究了一维多电子短程相互作用系统的CDW相激子的自陷，以阐明其在光激发后的晶格弛豫。描述弛豫过程的绝热势面是在表征系统的四个参数的宽范围内计算的：电子转移能T，e-p耦合能S，内部和内部的e-e排斥能U和V。结果表明，在强耦合情况下，激子弛豫到亚稳态基态，如SDW相岛，只有在中等耦合情况下，激子才弛豫到能隙中间的发光态.这些结果可以很好地解释Wolffram红盐的发光现象。
The self-trapping of exciton in the CDW phase of one-dimensional many-electron system with short-ranged electron-phonon(e-p) and electron-electron(e-e) interactions is studied by a variational method for exciton and in the adiabatic limit for phonons, so as to clarify its lattice relaxation after the light excitation. The adiabatic potential surface describing the relaxation process is calculated in a wide region of four parameters characterizing the system: the transfer energy of electron T , the e-p coupling energy S , intra- and inter-site e-e repulsive energies U and V . It is shown that in the strong coupling case S ≫2 T , the exciton relaxes to metastable ground states such as an island of SDW phase, and only in the inter-mediate case S ∼2 T it relaxes to a luminescent state localized in the middle of the energy-gap. These results can well explain the luminescence of Wolffram's red salt.