Negative Bogoliubov dispersion in exciton-polariton condensates
Negative Bogoliubov dispersion in exciton-polariton condensates
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DOI：
10.1103/physrevb.85.075130
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发表时间：
2012-02-29
影响因子：
3.7
通讯作者：
Yamamoto, Yoshihisa
中科院分区：
文献类型：
--
作者：
Byrnes, Tim;Horikiri, Tomoyuki;Yamamoto, Yoshihisa
Bogoliubov的理论指出，玻色-爱因斯坦凝聚体中的自相互作用效应在低动量下产生特征线性色散。博戈留波夫理论的一个奇特特征是，系统中的新准粒子是玻色子的创造算符和破坏算符的线性组合。在激子-极化激元凝聚体中，这给出了在光致发光（PL）发射中直接观察Bogoliubov色散的负分支的可能性。在这里，我们从理论上研究激子极化激元凝聚考虑水库效应的PL光谱。在足够高的激发密度下，负色散变得可见。我们还讨论了强水库耦合条件下发生弛豫振荡的可能性。发现这给出了使负分支可见的第二机制。
Bogoliubov's theory states that self-interaction effects in Bose-Einstein condensates produce a characteristic linear dispersion at lowmomenta. One of the curious features of Bogoliubov's theory is that the new quasiparticles in the system are linear combinations of creation and destruction operators of the bosons. In exciton-polariton condensates, this gives the possibility of directly observing the negative branch of the Bogoliubov dispersion in the photoluminescence (PL) emission. Here we theoretically examine the PL spectra of exciton-polariton condensates taking into account reservoir effects. At sufficiently high excitation densities, the negative dispersion becomes visible. We also discuss the possibility for relaxation oscillations to occur under conditions of strong reservoir coupling. This is found to give a secondary mechanism for making the negative branch visible.