论文标题
GAN/（藻类）n纳米结构中偶极激发量莫特过渡的复杂性
Complexity of dipolar exciton Mott transition in GaN/(AlGa)N nanostructures
论文作者
论文摘要
通过空间分辨的磁磁发光光谱谱图，在宽的gan/（al，ga）n量子中，在$ t = 7 $ k的宽gan/（al，ga）n量子中表现出了从偶极激发液到电子血浆的莫特过渡。随着光激发密度的增加，我们将系统从激发态驱动，其特征是磁通性行为，因此二次能量依赖于磁场，转移到未结合的电子孔状态，其特征在于发射能与磁场的线性移位。系统的复杂性需要考虑激子结合能的密度依赖性，以及具有相同数量级的激子 - 外激体相互作用和相关能量。我们将Mott Transition的载体密度估计为$ n_ \ Mathrm {Mott} \大约2 \ times 10^{11} $ cm $^{ - 2} $，并解决了此过程中激素相关性扮演的角色。我们的结果强烈依赖于光致发光的空间分辨率和载体传输的评估。我们表明，与GAAS/（AL，GA）作为系统相反，在GAN/（Al，GA）中，磁场的偶极磁磁体运输被磁场强烈淬灭，频带参数是这样的，因此传输保留了高达$ 9 $ t。
The Mott transition from a dipolar excitonic liquid to an electron-hole plasma is demonstrated in a wide GaN/(Al,Ga)N quantum well at $T=7$K by means of spatially-resolved magneto-photoluminescence spectroscopy. Increasing optical excitation density we drive the system from the excitonic state, characterized by a diamagnetic behavior and thus a quadratic energy dependence on the magnetic field, to the unbound electron-hole state, characterized by a linear shift of the emission energy with the magnetic field. The complexity of the system requires to take into account both the density-dependence of the exciton binding energy and the exciton-exciton interaction and correlation energy that are of the same order of magnitude. We estimate the carrier density at Mott transition as $n_\mathrm{Mott}\approx 2\times 10^{11}$cm$^{-2}$ and address the role played by excitonic correlations in this process. Our results strongly rely on the spatial resolution of the photoluminescence and the assessment of the carrier transport. We show, that in contrast to GaAs/(Al,Ga)As systems, where transport of dipolar magnetoexcitons is strongly quenched by the magnetic field due to exciton mass enhancement, in GaN/(Al,Ga)N the band parameters are such that the transport is preserved up to $9$T.
