中国物理B ›› 2012, Vol. 21 ›› Issue (5): 57302-057302.doi: 10.1088/1674-1056/21/5/057302
宋亚峰1,吕燕伍2,文伟3,刘祥林1,杨少延1,朱勤生1,王占国1
Song Ya-Feng(宋亚峰)a), Lü Yan-Wu(吕燕伍)b), Wen Wei(文伟)c), Liu Xiang-Lin(刘祥林)a), Yang Shao-Yan(杨少延)a), Zhu Qin-Sheng(朱勤生)a)†, and Wang Zhan-Guo(王占国)a)
摘要: The collective charge density excitations in a free-standing nanorod with a two-dimensional parabolic quantum well are investigated within the framework of Bohm--Pine's random-phase approximation in the two-subband model. The new simplified analytical expressions of the Coulomb interaction matrix elements and dielectric functions are derived and numerically discussed. In addition, the electron density and temperature dependences of dispersion features are also investigated. We find that in the two-dimensional parabolic quantum well, the intrasubband upper branch is coupled with the intersubband mode, which is quite different from other quasi-one-dimensional systems like a cylindrical quantum wire with an infinite rectangular potential. In addition, we also find that higher temperature results in the intersubband mode (with an energy of 12 meV (~ 3 THz)) becoming totally damped, which agrees well with the experimental results of Raman scattering in the literature. These interesting properties may provide useful references to the design of free-standing nanorod based devices.
中图分类号: (Collective excitations (including excitons, polarons, plasmons and other charge-density excitations))