Coherent signature of differential transmission signals in semiconductors: Theory and experiment
Coherent signature of differential transmission signals in semiconductors: Theory and experiment
复制标题
半导体中差分传输信号的相干特征：理论与实验
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
K. Köhler
中科院分区：
文献类型：
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作者：
G. Bartels;G. Cho;T. Dekorsy;H. Kurz;A. Stahl;K. Köhler
对GaAs/${mathrm{Al}}_{mathrm{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathrm{x}}$As量子阱在不同激发条件下的瞬态泵浦探测信号进行了理论和实验研究。计算是基于考虑高阶相关性的微观密度矩阵方法。我们提出了光谱解析瞬态，提供了对差分传输变化性质的见解。特别是与探测能量相关的重空穴量子拍的复杂相位特征，使得在泵浦探测信号中可以识别不同的微观过程。通过实验与时间分辨数据的相干部分和非相干部分进行了比较，验证了理论结果。与泡利阻塞贡献相比，我们发现库仑诱导相关在相干特征中起主导作用，直至${mathm {ensuremath{chi}}}^{(3)}$相关的四点水平。
Transient pump-probe signals of a GaAs/${mathrm{Al}}_{mathrm{x}}$${mathrm{Ga}}_{1mathrm{ensuremath{-}}mathrm{x}}$As quantum well are investigated both theoretically and experimentally for different excitation conditions. The calculations are based on a microscopic density-matrix approach taking higher-order correlations into account. We present spectrally resolved transients which provide insights into the nature of the differential transmission change. Especially the complex phase signature of heavy-holechar21{}light-hole quantum beats in dependence of the detection energy allows for an identification of different microscopic processes in the pump-probe signal. The theoretical results are verified experimentally by comparison with the coherent and incoherent parts of the time-resolved data. We find a dominant role of the Coulomb-induced correlations up to the ${mathrm{ensuremath{chi}}}^{(3)}$ relevant four-point level in the coherent signature in comparison to the Pauli blocking contributions.