2D磁场下磁激子的超快库仑诱导动力学
摘要
我们理论上研究了受垂直磁场约束的量子阱激子的超快非线性光学响应。我们指出，对于受约束于最低 Landau 能级的磁激子，其第三阶四向混合(FWM)极化由激子-激子相互作用主导。对于受排斥作用的相互作用， we identify two regimes in the time-evolution of the optical polarization characterized by exponential and power law decay of the FWM signal. We describe these regimes by deriving an analytical solution for the memory kernel of the two-exciton wave-function in strong magnetic field. For strong exciton-exciton interactions, the decay of the FWM signal is governed by an antibound resonance with an interaction-dependent decay rate. For weak interactions, the continuum of exciton-exciton scattering states leads to a long tail of the time-integrated FWM signal for negative time delays, which is described by the product of a power law and a logarithmic factor. By combining this analytic solution with numerical calculations, we study the crossover between the exponential and non-exponential regimes as a function of magnetic field. For attractive exciton-exciton interaction, we show that the time-evolution of the FWM signal is dominated by the biexcitonic effects.
引用
@article{arxiv.cond-mat/0008417,
title = {Ultrafast Coulomb-induced dynamics of 2D magnetoexcitons},
author = {T. V. Shahbazyan and N. Primozich and I. E. Perakis},
journal= {arXiv preprint arXiv:cond-mat/0008417},
year = {2009}
}
备注
41 pages with 11 figs