Muljarov E A, Zimmermann R
Institut für Physik der Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany.
Phys Rev Lett. 2007 May 4;98(18):187401. doi: 10.1103/PhysRevLett.98.187401. Epub 2007 May 1.
It is widely believed that, due to its discrete nature, excitonic states in a quantum dot coupled to dispersionless longitudinal-optical (LO) phonons form everlasting mixed states (exciton polarons) showing no line broadening in the spectrum. This is indeed true if the model is restricted to a limited number of excitonic states in a quantum dot. We show, however, that extending the model to a large number of states results in LO phonon-induced spectral broadening and complete decoherence of the optical response.
人们普遍认为，由于其离散性质，耦合到无色散纵向光学（LO）声子的量子点中的激子态会形成永恒的混合态（激子极化子），其光谱中没有线宽展宽。如果该模型仅限于量子点中有限数量的激子态，情况确实如此。然而，我们表明，将模型扩展到大量态会导致LO声子诱导的光谱展宽和光学响应的完全退相干。
