量子点调制的一维量子波导中声学声子输运和热导  

Acoustic phonon transport and thermal conductance in one-dimensional quantum waveguide modulated with quantum dots

作　　者：彭小芳[1] 王新军[1] 龚志强[1] 陈丽群[1] 

机构地区：[1]中南林业科技大学理学院,长沙410004

出　　处：《物理学报》2011年第12期438-446,共9页Acta Physica Sinica

基　　金：中南林业科技大学人才引进计划(批准号:104-0160)资助的课题~~

摘　　要：利用散射矩阵方法,比较了被一维凸形量子点、凹形量子点调制的量子线中膨胀模的声子输运和热导性质.研究结果表明:声子的输运概率与热导受制于量子点几何结构,具有凸形量子点结构的量子线中声子输运概率与热导KCV大于具有凹形量子点结构的量子线中声子输运概率与热导KCC.两者热导之比KCV/KCC依赖于一维量子点的具体结构,且随着温度及主量子线与量子点横截面的边长差ΔSL的增加而增加.两种具有不同散射结构的一维量子线中热输运性质的区别在于凸形量子点结构中膨胀模数量总是大于凹形量子点结构中膨胀模数量的缘故.By using scattering matrix method,we compare the propertics of acoustic phonon transport and thermal conductance in one-dimensional quantum waveguide modulated with both convex-shape and concave-shape quantum structures.The results show that the transmission spectra and thermal conductances are sensitive to the geometric structures of quantum dots,and the transmission rate and thermal conductance KCV in the convex-shape quantum structure are bigger than the transmission rate and thermal conductance KCC in the concave-shape quantum structure.The thermal conductance ratio KCV/KCC is dependent on the geometric detail of quantum dot,and the ratio increases with the increase of difference in side-length of the cross section between the quantum dot and the main quantum waveguide.The difference in thermal transport between the convex-shape and the concave-shape quantum structures originates from more excited dilatational acoustic modes in the convex-shape quantum structure than in the concave-shape quantum structure.

关 键 词：声学声子输运 热导 量子结构 

分 类 号：O488[理学—固体物理]