A THEORY OF PHOTOLUMINESCENCE FROM A TWO-DIMENSIONAL ELECTRON SYSTEM IN QUANTUM HALL REGIME

最近的光学实验，如磁致发光和非弹性光散射已经能够探测量子霍尔态在二维电子系统，除了量子输运测量。它为我们提供了量子霍尔态中激发态的信息，同时也为Wigner晶体的形成提供了新的认识。本文研究了调制掺杂n-GaAs/AlGaAs量子阱异质结构中电子-电子和电子-空穴多体相互作用引起的发光能量的磁振荡。主要结果如下：1利用介电函数的等离子体极近似，在最低朗道能级发现了光激发空穴自能的明显磁振荡。电子自能的相应位移几乎与磁场无关，这是由于电子自能的强趋势 ...更多信息 y表示屏蔽交换项和库仑空穴项之间的抵消。因此，带隙重整化的净磁场依赖性主要取决于空穴的自能。2计算了高磁场下n型非对称单量子威尔斯中光激发自由空穴和二维电子复合产生的光致发光能量。由于电子-空穴相互作用强度的变化，磁振荡在一定强度的外加电场下发生相变。3计算了n型单异质结构和量子威尔斯阱中与受主中空穴捕获相关的发光能量。在量子阱的情况下，光致发光能量表现出明显的磁振荡，其相位与自由空穴的情况相反。对异质结情况的详细研究表明，能量红移的幅度随着受主与异质结界面距离的增加而减小。计算出的特征很好地再现了Kukushkin等人最近的实验。

Recent optical experiments such as magnetoluminescence and inelasitic light scattering have been able to probe the quanum Hall state in a two-dimensionalelectron system, in addition to quantum transport measurements. It provides us the information of excited states in quantum Hall states as well as new insight into a formation of the Wigner crystals. Present work has explored a magnetic oscillation of luminescence energy associated with a recombination of a twodimensional electron with a photoexcited hole by taking into account many-body electron-electron and electron-hole interactions in modulation doped n-GaAs/AlGaAs quantum-well heterostructures. Our results are summarized as follows ;1 With use of the plasmon-pole approximation for dielectric function, we found clear magnetic oscillation ofthe self-energy of a photoexcited hole in the lowest Landau level. The corresponding shift for electron self-energy is nearly independent of the magnetic filed, which is due to the strong tendenc … More y for cancellation between the screened exchange term and the Coulomb-hole term. Therefore, the net magnetic field dependence of the band-gap renormalization is dominated by that of the self-energy of holes.2 The energy of photoluminesecne due to recombination of a photoexcited free hole and a two-dimensional electron is calculated in n-type asymmetric single quantum wells in high magnetic field. The magnetic oscillation undergoes a phase change at a certain strength of applied electric field because of the change in the strength of the electron-hole interaction.3 The luminescence energy associated with a hole trapped in an acceptor is calculated for n-type single heterostructures as well as quantum wells. In quantum well case, the photoluminescence energy exhibits a distinct magnetic oscillation whose phase is opposite to that for the case of a free hole. The detailed study for the hetero-junction case shwos that amplitude of the red shift in energy decreases as the distance between the acceptor and the hetero-interface increases. The calculated feature reproduces well the recent experiment by Kukushkin et al. Less