Symmetry-induced nonequilibrium distributions of bright and dark exciton states in single carbon nanotubes
Symmetry-induced nonequilibrium distributions of bright and dark exciton states in single carbon nanotubes
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DOI：
10.1103/physrevb.80.115436
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发表时间：
2009-09
影响因子：
3.7
通讯作者：
Ryusuke Matsunaga;Y. Miyauchi;K. Matsuda;Y. Kanemitsu
中科院分区：
文献类型：
--
作者：
Ryusuke Matsunaga;Y. Miyauchi;K. Matsuda;Y. Kanemitsu
我们研究了单根碳纳米管中亮激子和暗激子发光光谱的磁效应和温度效应。我们发现，在零磁场下，从亮到暗态的声子感生激子散射率仅比10K以下的暗激子复合速率大一个数量级。结果表明，由于波函数的奇偶性不同，激子在亮态和暗态之间的分布是不平衡的，Aharonov-Bohm通量增强了这两种态之间的声子诱导激子散射。我们的非平衡激子分布模型也可以解释在很低温度下的非零光致发光强度。
We investigated the magnetic and temperature dependence of the bright and dark exciton luminescence spectra in single carbon nanotubes. We found that the phonon-induced exciton scattering rate from the bright to the dark state is only one order of magnitude larger than the dark exciton recombination rate below 10 K at zero magnetic field. Our results indicate that excitons are nonequilibriumly distributed between the bright and dark states due to the different parities of the wave functions and that Aharonov-Bohm flux enhances the phonon-induced exciton scattering between these two states. Our nonequilibrium exciton distribution model can also explain the nonzero photoluminescence intensity at very low temperatures.