砷化銦單量子點藉應力調變激子能階

Abstract

砷化銦量子點的激子螢光具有精細結構分裂的性質，源於量子點的形狀不對稱。根據Bir-Pikus 漢米爾頓方程式來探討精細結構分裂，與量子點應變量之間的關係。我們嘗試利用壓電材料來對量子點外加應力；在實驗時激子能階確實會隨著外加應力而改變，證實了外加應力的確是能對量子點形狀造成影響。且激子精細結構分裂的大小也能靠外加應力來改變；實驗數據也能和理論值相符合。代表利用外加應力的方式，是有可能將單量子點的激子能態給變為簡併態。

The fine structure splitting (FSS) of exciton emission from single InAs/GaAs quantum dots (QDs) are investigated. The excitonic FSS is attributed to the QD shape asymmetry reduction. Based on the formulism of the Bir-Pikus Hamiltonian, the interplay between the FSS and stress are discussed. We apply the stress to the QD by piezoelectric materials. In the experiment, the excitonic energy level does change with the external stress, confirming the external stress can indeed affect the shape of quantum dots. The FSS also can be changed by the external stress. Experimental data are consistent with the theoretical anticipation. Using the way of applying stresses, the single quantum dot excitonic states are possible to become degenerate states.